HomeMy WebLinkAboutStaff Report to the Sustainability Commission - Tree Package July 2025 Meeting
Staff Memo to the Sustainability Commission
Date: 22 July 2025
Subject: Ordinance Review and Supporting Documents
From: Office of Sustainability
Summary:
Staff is introducing the drafted text of the Tree Ordinance with the opportunity for the
Sustainability Commission to provide feedback and comments on the agenda item. The
proposed ordinance aims to establish clearer standards and requirements for the management
and protection of trees within the City.
Recommendation:
Read and review the proposed amendments to Title 11 (Peace, Morals, and Safety) of the Palm
Springs Municipal Code adding Chapters 11.46 (“Public Tree Management) and Chapter 11.47
(“Private Tree Management”). Provide direction on supporting materials including the
Recommended Species List.
Background:
In October 2023, staff introduced the concept of a citywide tree ordinance as part of the City’s
urban forestry goals outlined in the 2016 Sustainability Master Plan, which calls for the City to
“adopt a tree protection ordinance that addresses tree replacement and removal”. The intent of
the ordinance is to establish clear regulatory framework to help preserve the City’s urban
canopy, protect significant trees, and guide responsible tree management on both public and
private properties. This is a key step in the larger development of a Citywide Urban Forestry
Program.
Since its introduction, staff has provided regular updates on the progress of ordinance to the
Sustainability Commission and Climate Action Subcommittee as a recurring agenda item,
including the progress of key supporting resources such as the Recommended Species List and
Technical Maintenance Manual. In April 2024, the ordinance concept and case examples were
also presented to the Planning Commission as a study session item for further input.
Over the past year and a half, staff has also collaborated with internal stakeholders to review
draft language, align with existing procedures, and gather feedback to ensure consistency with
City goals. The internal stakeholders include Planning, Public Works, Code Enforcement, Parks,
and Engineering. In parallel with the ordinance development, staff has also worked with the IT
Department’s GIS team to develop and launch a dedicated City Urban Forestry Website, which
will serve as a public-facing platform for program information, resources, and ongoing
community engagement.
Staff Analysis:
The proposed ordinance will amend Title 11 (“Peace, Morals, and Safety) of the Palm Springs
Municipal Code by adding two chapters, Chapter 11.46 (“Public Tree Management”) and
Chapter 11.47 (“Private Tree Management”). The chapters build on and align with existing
Municipal Code provisions such as the "Property Maintenance” and “Excessive Plant Growth”
subchapters identified in Chapter 11.72 (“Public Nuisances”).
The new additional chapters expand on the existing code by establishing clear and consistent
tree management standards and procedures that apply to different types of property:
• Chapter 11.46 - Public Tree Management: Establishes the City’s responsibility for
planting, maintaining, removing and replacing trees in areas managed by the City such
as Parks, City Properties, and other City-managed areas.
• Chapter 11.47 - Private Tree Management: Establishes clear standards and
procedures for the maintenance, removal and replacement of trees on private properties
that are subject to approved landscape plans.
Key provisions include:
• Protected Trees: The ordinance defines “Protected Trees” as those with a trunk
diameter of 12” inches or greater located on public property or on private property
subject to an approved landscape plan. Trees may also be designated as protected
through the development review process or by the City based on their significance.
• Criteria for Tree Removal: Tree removal may be permitted based on the consideration
of factors such as site constraints, tree health, infrastructure conflicts and site
development needs.
• Criteria for Replacement Trees: Tree replacement may be required for tree removals.
Trees must be replaced at a 1:1 ratio, while “Protected Trees” require a 2:1 ratio. Palm
trees that require removal shall be replaced at a like-for-like 1:1 ratio regardless of
protected tree designation. Replacement trees shall be selected from the City’s
recommended species list and must be appropriate for the planting site.
The implementation of a tree ordinance will allow the City to take advantage of a range of future
opportunities that support the urban forestry program. One notable example is the eligibility for a
“Tree City USA” recognition from the Arbor Day Foundation, which requires participating and
awarded cities to have an adopted tree ordinance in place.
Additionally, having a formal tree ordinance can enhance the City’s competitiveness for state,
federal, and other funding opportunities, such as those offered through CalFire’s Urban and
Community Forestry Program. Grants supporting tree planting, heat mitigation, canopy equity,
and the development of long-term management strategies will be essential in meeting our
climate mitigation and adaptation goals.
In addition to the proposed ordinance text, staff has developed supporting tools and resources
to guide the development and implementation of the City’s long-term urban forestry goals.
The supporting resources include:
• Recommended Species List: The approved list of species suitable for planting and
replacing trees within the City, considering factors such as height, canopy size, water
needs and compatibility with infrastructure.
• Technical Maintenance Manual: The reference document outlining best management
practices for tree care, maintenance, pruning, and planting. This manual is a guide to
provide consistent guidance for City departments, developers, and contractors, and
support long-term tree health and safety in both public and private landscapes.
• Urban Forestry Website: An online platform designed to serve as a central hub for
public information, educational materials, and program updates for the City’s Urban
Forestry Program. The website will include interactive maps, ordinance details, surveys
and resources.
Together, these resources will help standardize tree-related processes, preserve the City’s
urban canopy, and support public awareness and transparency as the ordinance is
implemented.
To ensure the ordinance and its supporting materials reflect Citywide priorities and operational
realities, staff engaged multiple internal stakeholders through the development process.
Departments including Planning, Public Works, Parks, Engineering and Code Enforcement
provided critical feedback on both the ordinance text and supporting documents, helping align
the program with existing policies and procedures. The City’s contracted arborist firm, West
Coast Arborists, drafted the Recommended Species List and Technical Manual and has
provided subject matter expertise.
Staff also worked closely with the City Attorney’s Office to review, edit, and refine the ordinance
language. This collaboration ensured the proposed chapters are legally sound, consistent with
existing sections of the Municipal Code, and clearly structured for implementation and
enforcement.
Conclusion:
Staff recommends that the Commission review the drafted Ordinance and provide feedback
and/or comments. The ordinance will be brought back to the commission as a voting item in a
subsequent Fall 2025 meeting.
Attachments:
A. Ordinance No.______
B. Technical Manual Draft & Recommended Species List
ATTACHMENT A
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ORDINANCE DRAFT NO. XXXX
AN ORDINANCE OF THE CITY OF PALM SPRINGS,
CALIFORNIA, AMENDING TITLE 11 (PEACE, MORALS, AND
SAFETY) OF THE PALM SPRINGS MUNICIPAL CODE TO
ADD CHAPTER 11.46 (“PUBLIC TREE MANAGEMENT”)
AND CHAPTER 11.47 (“PRIVATE TREE MANAGEMENT”)
THE CITY COUNCIL OF THE CITY OF PALM SPRINGS DOES HEREBY ORDAIN AS
FOLLOWS:
WHEREAS, the City of Palm Springs recognizes the importance of trees to the residents
of and visitors to Palm Springs; and
WHEREAS, the community has an interest in preserving trees as important natural
resources which provide scale, color, aroma, visual buffers between land uses, and increased
property values, and which contribute to the environment by improving general aesthetics,
modifying temperatures by providing shade, reducing heat and glare, reducing wind velocity,
purifying and replenishing oxygen, controlling soil erosion, and providing wildlife habitat; and
WHEREAS, the purpose of this ordinance includes the need to regulate the placement and
selection of new trees to minimize problems in public spaces, to establish requirements for the
preservation and proper maintenance of existing and future public and private trees, and to promote
the planting and preservation of public and private trees in Palm Springs; and
WHEREAS, it is also the purpose of this ordinance to promote and protect the public
health, safety, and general welfare by regulating the planning, planting, maintenance, removal and
replacement of city-owned trees in street rights of way, city parks and other city property; and
WHEREAS, it is also the purpose of this ordinance is to preserve and protect trees located
on private property within the City, and to establish standards for their maintenance, removal, and
planting. It is the City’s intent to encourage the preservation of existing trees and the incorporation
of new trees and landscaping in development, while promoting responsible management practices
in accordance with this chapter.
WHEREAS, this ordinance intends to preserve and enhance property values by conserving
and enhancing the distinctive and unique aesthetic character of the city’s various areas, which is
significantly contributed to by the presence of public and private trees; and
WHEREAS, this ordinance also supports the protection of the natural environment by
promoting tree preservation, reducing unnecessary or improper tree removal, and encouraging the
planting of new trees in the City; and
WHEREAS, the City Council previously adopted the City of Palm Springs 2016
Sustainability Master Plan which established a goal of earning the “Tree City USA” designation
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awarded by the National Arbor Day foundation, one requirement of which is the adoption of an
ordinance to provide guidance for planting, maintaining, and removing trees from public places.
THE CITY COUNCIL OF THE CITY OF PALM SPRINGS DOES HEREBY ORDAIN AS
FOLLOWS:
SECTION 1. The above recitals are true and correct and are hereby incorporated herein by this
reference.
SECTION 2. Pursuant to the foregoing recitals and findings, the City Council hereby adopts
Ordinance No. _____, amending Title 11 (Peace, Morals, and Safety) of the Municipal Code to
add Chapter 11.46 (Public Tree Management) and Chapter 11.47 (Private Tree Management), as
follows:
Chapter 11 .46 PUBLIC TREE MANAGEMENT
11.46.010 - Purpose.
The purpose of this Ordinance is to preserve and protect the health, longevity, and safety of Public
Trees as an important resource, to promote the health, safety and quality of life of residents and
visitors, and to enhance the appearance of the City of Palm Springs, to clearly define responsibility
for the maintenance of Public Trees and shrubs, and to adopt best management practices and
industry standards for the planting and maintenance of Public Trees and shrubs.
It is the policy of the city to enhance a healthy urban forest and conduct a consistent and adequate
program for maintaining and preserving trees. In addition, it is the policy of the city to encourage
new tree, shrub, and groundcover planting, contributing to a flourishing urban forest in accordance
with the requirements of this Chapter.
11.46.20 - Definitions.
“Certified Arborist” means a Person who has received education and experience in either
arboriculture or horticulture and holds either a Registered Consulting Arborist (RCA) certification
from the American Society of Consulting Arborists (ASCA) or an ISA Certified Arborist
designation from the International Society of Arboriculture (ISA). The Certified Arborist may be
a City employee, City contractor, or other City designee.
“City” means the City of Palm Springs.
“City Manager” means the City Manager and/or their designee(s).
“Critical Root Zone” or “CRZ” mean the distance from the trunk that equals 1.25-foot radius for
every inch of the tree’s diameter.
“Damage” means any action which causes harm, injury, death, mutilation, stapling or
disfigurement of a tree, including but not limited to uprooting; severance of all or part of the root
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system or main trunk; storage of material on or compaction of surrounding soil; a substantial
change in the natural grade above a root system or around a trunk; surrounding the tree with
impervious materials; attachment of any rope, wire, nail, advertising poster, or similar devices;
setting fire or intentionally or negligently permitting any fire to burn when such fire or the heat
therefrom will injure any part of any tree; or any trauma caused by accident, negligence or
collision.
“Development” means any work upon property in the city which require a subdivision, planned
development district, conditional use permit, development permit, architectural application,
variance, land permit, building permit, demolition permit, or other city approval or which involves
excavation, landscaping or construction within the dripline area of a Protected Tree or is subject
to requirements of the California Water Efficient Landscape Ordinance (MWELO).
“Enforcement Action” or “Enforcement Actions” means an action or actions of the City to address
non-compliance with this Chapter including, but not limited to, issuing administrative citations,
fines, penalties, or any other remedies.
“Enforcement Officer” means a code compliance officer, police officer, building inspector, or any
other city employee or contractor designated by the City Manager to enforce the provisions of the
Palm Springs Municipal Code and granted authority to issue notices and administrative citations
pursuant to this title. The term “Enforcement Officer” also includes any city employee or official
expressly provided enforcement authority pursuant to the provisions of this code.
“Maintain” or “Maintenance” means any of the following actions: pruning, spraying, mulching,
fertilizing, cultivating, supporting, treating for disease, injury or pests, promoting public safety, or
any other similar act affecting the life, growth, health or beauty of Public Trees.
“Municipal Arborist” means a certified arborist employed by or contracted by the City to manage,
assess, and maintain trees within the City.
“Nuisance” means any tree, or limb thereof, that has an infectious disease or insect; is dead or
dying, obstructs the view of traffic signs or the free passage of pedestrians or vehicles; or threatens
public health, safety, or welfare.
“Parkway” means that portion of a street other than a roadway or sidewalk.
“Person” means any individual, firm, association, corporation, or other entity type and any agent,
employee or representative thereof.
“Recommended Species List” means an official list of desirable tree species for planting within
City limits. This list will be maintained and updated as necessary by the City Manager.
“Protected Tree” means:
1. Any tree having a trunk diameter of at least twelve (12) inches or greater on publicly owned
property or all private property that is subject to an approved landscape plan, except those
having a high potential to invade and high ecological impacts in the region as defined by
the California Invasive Plant Council.
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2. Any tree designated for protection during review and/or approval of a Development
project.
3. Any other tree or similar plant designated by the City Manager to have substantial
importance. Substantial importance shall include, but not be limited to, trees that are
significant to the community, to animals, or to other plants.
This definition shall not include any tree grown in or held for sale by a licensed nursery, or
trees planted or grown as a part of a tree planting program, including but not limited to
those programs that may be held annually on Arbor Day.
“Public Property” means parks, parkways, playgrounds, areas around public buildings, squares
and places such as traffic divider strips or islands, and all other areas under supervision and
maintenance of the City and which are now, or may hereafter, be dedicated to public use.
“Public Tree” means any tree or shrub, whether singular or plural, whose trunk is planted on Public
Property or any other right of way owned or controlled by the city through an easement, license,
fee title, or other permissive grant of use and maintained by the city.
“Shrub” means woody vegetation or a woody plant having multiple stems and bearing foliage from
the ground up.
“Top” or “Topping” means the non-standard practice of cutting back of limbs to stubs within a
tree’s crown to such a degree so as to remove the normal canopy and disfigure the tree.
“Tree” means any woody perennial plant, usually having a single main axis or trunk, but including
specimens of such plants having multiple trunks.
“Tree Management Program Rules” shall mean the rules created and maintained by the City
Manager that shall further the goals and requirements of this Chapter.
Such rules shall enhance and provide clarity to this Chapter, provide additional details and
requirements for the public, city departments, and other interested parties, and shall be
considered binding rules upon the public, city departments, and all other parties.
Such rules may be updated from time to time, if such updates are determined to be
necessary by the City Manager. Any changes to the rules shall be posted to the City website
and available in draft form at City Hall at least 60 days before the rules go into effect.
“Tree Protection Zone” or “TPZ” means an area of protection surrounding the tree trunk intended
to protect the tree, the roots and the soil during construction or Development.
“Trim” or “Prune” means the removal of limbs and fruit and branches as necessary to properly
train the trees to promote healthy growth, for public safety for aesthetic purposes, to provide
clearance for traffic control, and vehicles. Trees shall be trimmed and pruned annua lly or
biannually, depending upon the type of tree.
“Visibility Triangle” and/or “Sight Distance” means the unobstructed line of sight needed for
navigation around corners, intersections, driveways, or other similar roadway features.
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11.46.030 - Authority and Power
a) Delegation of authority and responsibility. The City Manager shall have full authority and
responsibility to plant, prune, maintain, remove and replace trees and woody plants growing
in or upon all municipal streets, rights-of-ways owned or controlled by the City, city parks, and
other Public Property. This shall include the removal of trees that may threaten or obstruct
public works projects or electrical, telephone, gas, or any municipal water or sewer line, or any
tree that is affected by fungus, insect, or other pest disease that may threaten the well-being of
other trees in city limits.
b) Interference. No Person shall hinder, prevent, delay, or interfere with any City employee or
contractor while engaged in carrying out the execution or enforcement of this Chapter.
c) Interpretation. All references in this Chapter to a singular tree or shrub shall also include
multiple trees and all references to multiple trees or shrubs shall also include the singular.
11.46.040- Tree Planting and Care Standards
a) Standards. All planting and maintenance of Public Trees shall conform to the American
National Standards Institute (ANSI) A-3000 “Standards for Tree Care Operations” and shall
follow all tree care Best Management Practices (BMPs) published by the International Society
of Arboriculture.
b) Requirements of franchise utility companies. The maintenance, including pruning or other
alterations, of Public Trees for utility clearance shall conform to all applicable public utility
industry standards and shall comply with all requirements of this Chapter.
Public utility companies subject to the jurisdiction of the California Public Utilities
Commission may perform pruning or other alteration of Public Trees, as is necessary, to
comply with the safety regulations of said commission and to maintain the safe operation of
their facilities. On an annual basis, such companies shall notify the City Manager at least three
working days prior to undertaking any such pruning or other work on a Public Tree, except in
cases of emergency. The City Manager may cause such pruning work to be inspected, when
necessary to ensure that the pruning practices and procedures as referenced in this Chapter and
in the City’s Tree Management Program Rules are followed.
c) Recommended Species List. The City Manager shall maintain the Recommended Species List
for planting of trees within City limits. Trees from the Recommended Species List may be
planted without prior City approval; any other species may only be planted with prior, written
approval from the City Manager. The City reserves the right to approve or deny a request for
species not on the Recommended Species List.
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d) Planting Distances. The City Manager shall develop and maintain an official set of spacing
requirements for the planting of trees on Public Property. No tree may be planted within the
Visibility Triangle of a street intersection or within 10 feet of a fire hydrant.
e) Planting Trees under electric utility lines. Only trees or shrubs that have a maximum mature
height of 20 feet or less on the Recommended Species List may be planted under or within 15
lateral feet of any overhead utility wire.
11.46.050- Prohibition Against Harming Public Trees
a) It shall be unlawful for any Person to damage, remove, or cause the damage or removal of a
Public Tree without prior, written approval from the City Manager.
b) It shall be unlawful for any Person to attach any cable, wire, sign, or any other object to any
street tree or to any other tree located on Public Property without prior, written permission
from the City Manager.
c) It shall be unlawful for any Person to top any tree that is located on Public Property. Trees
severely damaged by storms or other causes, where best pruning practices are impractical may
be exempted from this provision at the determination of the City Manager.
d) Any Person or City department performing construction work near any Public Property shall
consult with the City Manager prior to commencing the work. The City Manager shall review
the work plan and shall require that the Person or City department shall employ all appropriate
measures to protect the tree(s), according to procedure contained in the Best Management
Practices (BMPs) for “Managing Trees During Construction” published by the International
Society of Arborist.
e) Each violation of this section as determined and notified by the City Manager shall constitute
a separate violation, punishable by fines and penalties under [section #], in addition to
mitigation values placed on the tree(s) removed or damaged in violation of this Chapter.
f) Mitigation values shall be determined by the City Manager after consultation with a Certified
Arborist. Any fee charged by a Certified Arborist pursuant to this section shall be added to the
mitigation value assessment owed by the violator.
11.46.060- Replacement of Public Trees
Public Trees that are damaged, removed or require removal shall be replaced in accordance with
guidelines set by the City Manager and shall conform to the replacement criteria outlined in
Chapter 11.47
11.46.070- Development Conditions
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Development approvals for properties containing Public Trees shall adhere to standards and
requirements outlined in this Chapter and as may be determined necessary by the City, ensuring
the protection of such trees during construction.
11.46.080- Certain Trees Declared a Nuisance
a) Property on which overgrown, dead, diseased, or decayed trees, weeds or other vegetation that
are likely to harbor rats, pigeons, vermin, and other nuisances, or constitute a fire hazard or
other condition that is dangerous to, or otherwise poses a risk of harm to the publi c health,
safety, or welfare, or constitutes visual blight or reduces the aesthetic appearance of the
neighborhood or is offensive to the senses or is detrimental to the use and enjoyment of nearby
properties or reduces nearby property values is a public nuisance.
b) Any tree, limb thereof, or stump on private property determined to have contracted a lethal,
communicable disease or insect; to be dead or dying; to obstruct the view of traffic signs or the
free passage of pedestrians or vehicles; or that threatens public health, safety, and welfare
through a process established by the City Manager is declared a nuisance and the City may
require its treatment or removal.
11.46.090- Violation and Penalty
a) The City may take Enforcement Actions, including the issuance of an administrative citation
and assessment of a fine, against any Person for violating this chapter. The City’s procedures
on the imposition of administrative fines under Chapter 1.06 shall govern the imposition,
enforcement, collection and review of administrative citations issued to enforce this Chapter
and any rule or regulation adopted pursuant to this Chapter.
b) The loss of or damage to any unlawfully removed or damaged Public Tree or tree with
significant importance, as determined by the Enforcement Officer, will require restitution to
the City. In addition to any applicable penalties, any Person who willfully injures, damages,
destroys, removes, or relocates any Public Tree or tree with significant importance in violation
of this Chapter shall be responsible for proper restitution in the form of replacement trees or
fees in lieu of replacement, tree installation costs, Certified Arborist fees and similar related
costs, as determined by the City Manager.
11.46.100- Procedures for Citations and Appeals
Prior to taking any Enforcement Action against any Person for violating this Chapter, the City shall
first notify the Person and provide an opportunity to correct the violation through the issuance of
a Notice of Violation by the Enforcement Officer. Notices shall be sent to the owner at the official
address of the owner maintained by the tax collector for the City or if no such address is available,
to the owner at the address of the residential dwelling or commercial property, depending upon
available information. This notice shall contain information required by Palm Springs Municipal
Code section 1.06.030 (b). The notice shall state the Person, business, or entity has 60 Days to
correct the violation.
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11.46.110- Local Government Disclaims Liability
Nothing contained in this section shall be interpreted to impose any liability upon the City, its
officers, employees, or agents, nor to relieve the owner of any private property from the duty to
keep any Tree, Shrub or plant located upon the adjacent Planting Strip or upon the owner’s private
property from becoming hazard or public nuisance.
Chapter 11.47 PRIVATE TREE MANAGEMENT
11.47.010 - Purpose
The purpose of this chapter is to preserve and protect trees located on private property within the
City, and to establish standards for their maintenance, removal, and planting. It is the City’s intent
to encourage the preservation of existing trees and the incorporation of new trees and landscaping
in development, while promoting responsible management practices in accordance with this
chapter.
11.47.020- Definitions.
“Approved Landscape Plan” any landscaping or landscape plan approved by the City as part of
any permit or entitlement process, including, but not limited to, a building permit, grading permit,
land use permit, conditional use permit, development permit, planned development district, and
architectural review.
“Authorized Agent” means a person who has been designated and approved in writing by the
property owner of record to act on his, her or their behalf in matters pursuant to this chapter.
“Certified Arborist” means a person who has received education and experience in arboriculture
or horticulture and holds either a Registered Consulting Arborist (RCA) certification from the
American Society of Consulting Arborists (ASCA) or an ISA Certified Arborist designation from
the International Society of Arboriculture (ISA). The Certified Arborist may be a City employee,
City contractor, or other City designee.
“City” means the City of Palm Springs.
“City Manager” means the City Manager and/or their designee(s).
“Critical Root Zone” or “CRZ” mean the distance from the trunk that equals 1.25-foot radius for
every inch of the tree’s diameter.
“Damage” means any action which causes harm, injury, death, mutilation, stapling or
disfigurement of a tree, including but not limited to uprooting; severance of all or part of the root
system or main trunk; storage of material on or compaction of surrounding soil; a substantial
change in the natural grade above a root system or around a trunk; surrounding the tree with
impervious materials; attachment of any rope, wire, nail, advertising poster, or similar devices;
setting fire or intentionally or negligently permitting any fire to burn when such fire or the heat
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therefrom will injure any part of any tree; or any trauma caused by accident, negligence or
collision.
“Development” means any work upon property in the City which require a subdivision, planned
development district, conditional use permit, architectural review, variance, land permit, building
permit, demolition permit, or other City approval or which involves excavation, landscaping or
construction within the dripline area of a Protected Tree or is subject to requirements of the
California Water Model Efficient Landscape Ordinance (MWELO).
“Enforcement Action” or “Enforcement Actions” means an action or actions of the City to address
non-compliance with this Chapter including, but not limited to, issuing administrative citations,
fines, penalties, or any other remedies.
“Enforcement Officer” means a code compliance officer, police officer, building inspector, or any
other city employee designated by the City Manager to enforce the provisions of the Palm Springs
Municipal Code and granted authority to issue notices and administrative citations pursuant to this
title. The term “Enforcement Officer” also includes any city employee or official expressly
provided enforcement authority pursuant to the provisions of this code.
“Maintain” or “Maintenance” means any of the following actions: pruning, spraying, mulching,
fertilizing, cultivating, supporting, treating for disease, injury or pests, promoting public safety, or
any other similar act affecting the life, growth, health or beauty of Public Trees.
“Nuisance” means any tree, or limb thereof, that has an infectious disease or insect; is dead or
dying, obstructs the view of traffic signs or the free passage of pedestrians or vehicles; or threatens
public health, safety, or welfare.
“Parkway” means that portion of a street other than a roadway or sidewalk.
“Person” means any individual, firm, association or corporation, or other entity type and any agent,
employee or representative thereof.
“Recommended Species List” means an official list of desirable tree species for planting within
the City limits. This list will be maintained and updated as necessary by the City Manager.
“Protected Tree” means:
1. Any tree having a trunk diameter of at least twelve (12) inches or greater on publicly owned
property or all private property that is subject to an approved landscape plan, except those
having a high potential to invade and high ecological impacts in the region as defined by
the California Invasive Plant Council.
2. Any tree designated for protection during review and approval of a development project.
3. Any other tree or similar plant designated by the City to have substantial importance shall
include, but not be limited to, trees that are significant to the community, to animals, or to
other plants.
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This definition shall not include any tree grown in or held for sale by a licensed nursery, or
trees planted or grown as a part of a tree planting program, including but not limited to
those programs that may be held annually on Arbor Day.
“Private Property” shall include all land owned by private interest, and not designated City owned
land or under the supervision and maintenance of the City.
“Public Property” means parks, parkways, playgrounds, areas around public buildings, squares
and places such as traffic divider strips or islands, and all other areas under supervision and
maintenance of the City and which are now, or may hereafter, be dedicated to public use.
“Shrub” means woody vegetation or a woody plant having multiple stems and bearing foliage from
the ground up.
“Top” or “Topping” means the non-standard practice of cutting back of limbs to stubs within a
tree’s crown to such a degree so as to remove the normal canopy and disfigure the tree.
“Tree” means any woody perennial plant, usually having a single main axis or trunk, but including
specimens of such plants having multiple trunks.
“Tree Management Program Rules” shall mean the rules created and maintained by the City
Manager that shall further the goals and requirements of this Chapter.
Such rules shall enhance and provide more clarity to this Chapter, provide additional details
and requirements for the public, city departments, and other interested parties, and shall be
considered binding rules upon the public, city departments, and all other parties.
Such rules may be updated from time to time, if such updates are determined to be
necessary by the City Manager. Any changes to the rules shall be posted to the City website
and available in draft form at City Hall at least 60 days before the rules go into effect.
“Tree Protection Zone” or “TPZ” means an area of protection surrounding the tree trunk intended
to protect the tree, the roots and the soil during construction or development.
“Tree Stump” means any portion of the base or trunk of a tree and its roots that remain after a tree
is removed. For purposes of this chapter, a “tree stump” must have a diameter of at least six (6)
inches or greater.
“Trim” or “Prune” means the removal of limbs and fruit and branches as necessary to properly
train the trees to promote healthy growth, for public safety for aesthetic purposes, to provide
clearance for traffic control, and vehicles. Trees shall be trimmed and pruned annually or
biannually, depending upon the type of tree.
“Visibility Triangle” and/or “Sight Distance” means the unobstructed line of sight needed for
navigation around corners, intersections, driveways, or other similar roadway features.
11.47.030- Applicability
This Chapter is applicable to properties subject to an Approved Landscape Plan application as
defined in Section 94.04.00(C)(3).
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This Chapter shall not apply to the single-family properties not subject to an Approved Landscape
Plan or a minor architectural review application as defined in Section 94.04.00(C)(3).
11.47.040- Authority and Power
a) Delegation of authority and responsibility. The City Manager shall have authority to
approve or deny the planting, removal and/or replacement of trees planted on privately
owned property subject to an approved landscape plan or as otherwise regulated by this
Chapter. The City Manager shall have the authority and responsibility to administer and
enforce the provisions of this chapter.
11.47.050- Care of Trees on Private property
a) The City shall maintain an updated list of recommended tree species for planting within
City limits, in accordance with the standards outlined in this Chapter.
b) All property owners shall adhere to the maintenance standards established by the City. This
includes avoiding any action that could foreseeably lead to the death or permanent damage
of a tree’s health. Such actions include, but are not limited to, topping, girdling, poisoning,
unauthorized relocation or transportation of a tree, and activities such as trenching,
excavating, altering the grade, or paving within the Tree Protection Zone.
The property owner shall also adhere to the maintenance standards of excessive plant
growth outlined in Section 11.150.170 in Chapter 11.72 PUBLIC NUISANCES.
c) All landscaping improvements shall also conform to the standards and requirements
outlined Section 11.72.170 in Chapter 11.72 PUBLIC NUISANCES.
d) All irrigation design plans shall conform to the standards and requirements outlined in
Section 8.60.070 in Chapter 8.60 WATER EFFICIENT LANDSCAPING where
applicable.
e) Any tree, limb thereof, or stump on private property determined to have contracted a lethal,
communicable disease or insect; to be dead or dying; to obstruct the view of traffic signs
or the free passage of pedestrians or vehicles; or that threatens public health, safety, and
welfare through a process established by the City Manager is declared a nuisance and the
City may require its treatment or removal.
f) Private property owners have the duty, at their sole expense, to remove or treat nuisance
trees on their property. The City may remove such trees at the owner’s expense if the owner
does not comply with treatment and/or removal as specified by the Enforcement Officer or
the City Manager within the written notification period.
g) The Enforcement Officer shall cause a notice of violation to be issued to the property owner
or other responsible Person to abate a hazard whenever the Enforcement Officer has
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determined that a hazard exists. This enforcement authority shall be in addition to the
enforcement authority granted to the City Manager. The City shall abate such hazard in
accordance with the regulations of Chapter 11.72 (Public Nuisances).
11.47.060- Removal of Trees
a) No Person shall remove a tree without first obtaining written approval from the City,
obtained through the formal process as prescribed by the City. The approval may be
granted, in the city’s discretion, on the condition that the property owner or authorized
agent bears the full cost of the removal process, cost of planting any replacement tree(s)
and, when required, the cost of a Certified Arborist consultation and related costs.
b) The removal of a Tree shall be completed within sixty (60) days of the date of City
approval. The time for completion of the tree removal work may be extended if there is
evidence provided to the City that the tree(s) subject to removal approval contain nests (or
eggs) of birds that are designated as protected under the Migratory Bird Treaty Act and
California Department of Fish and Game Code.
If the City determines that the tree contains such nests or eggs, the City may extend the
removal time for up to ninety (90) days following determination by a qualified biologist or
ornithologist that the nest is inactive.
11.47.070- Criteria for the Removal of Trees
Removal of a tree shall be based upon consideration of one or more of the following criteria:
a) The tree proposed for removal is unsuitable to the planting area in that the area is too small
to accommodate the height, trunk diameter and canopy or root zone of the tree.
b) The tree negatively impacts improvements in the public right of way and/or repair of
damaged public infrastructure is not possible without removal of the tree.
c) The topography or other conditions of the building site renders removal necessary to the
development of the site.
d) Removal of the tree will not have an adverse impact on adjacent properties by exposing
undesirable features of adjacent structures and/or reducing the beneficial aspects of shading
or screening.
e) Removal of the tree will not have an adverse impact on the established public streetscape
or neighborhood aesthetics.
f) Replacement trees have been proposed to maintain the urban forest canopy and the
replacement trees are more appropriate to the site location and to the planting conditions.
11.47.080- Criteria for Replacement Trees
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In order to maintain and expand the City’s urban forest, replacement trees may be required as a
condition of approval for each tree removal.
a) Trees requiring removal shall be replaced on a one-to one ratio (meaning one tree planted for
every one tree removed). Trees designated as a Protected Tree shall require a two-to-one ratio
for replacement.
b) Palm trees requiring removal shall be replaced on a one-to-one ratio regardless of protected
tree designation.
c) Replacement tree(s) will be evaluated based on the industry standard for mature height of
suggested species and any potential view impacts related to the location and mature height.
Replacement may not be required when:
1. Replacement trees will interfere with overhead or underground utilities.
2. The site, as determined by staff and/or an ISA certified arborist, is not
suitable for replanting due to topography, microclimate conditions, size
of planting area, negative impacts to the public right of way, adverse
impacts to infrastructure and/or soil conditions.
d) The City Manager shall determine the requirements for the tree replacements and shall approve
the species of replacement tree(s) on private property subject to an approved landscape plan.
e) Replacement trees shall be a minimum of 24-inch box size or larger, unless otherwise directed
by the City Manager. Any replacement tree(s) shall be installed within one hundred eighty (60)
days after the date the tree is removed from the property, unless other installation deadlines or
requirements are provided for by the City Manager.
f) Replacement trees that are not on the recommended species list shall require written approval
from the City Manager. The City Manager’s decision shall be final and not subject to appeal.
11.47.090- Tree Protection During Land Development
a) Prior to the receipt of demolition, grading, land development or building permits or
approvals, including for construction, reconstruction or repair of sidewalks or curbs, the
applicant shall obtain a tree assessment for all trees within the construction limits of the
development site.
b) Establishment of tree protection zones.
a. To the maximum extent possible, all trees shall be preserved and the loss or damage
shall be minimized.
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b. A tree shall be considered preserved if there is no disturbance within the tree
protection zone. Disturbance includes earth disturbances, earth compaction,
vehicular and foot traffic, material stockpiling or the construction of all proposed
improvement or utilities.
c. A permanent Tree Protection Zone surrounding both preserved and planted trees
shall be established to protect the critical root zone and tree canopy. The TPZ shall
be a circle encompassing the CRZ, a 1.25-foot radius for each inch of the tree
trunk’s diameter. The TPZ shall apply during the construction phase as well.
d. The TPZ shall be protected by appropriate barriers as determined by the City.
e. There shall be no disturbance permitted within the TPZ, including, but not limited
to, intrusion into the soil through digging, trenching and grading, no activities that
will compact the soil and no stockpiling of construction materials without prior
approval by the City.
11.47.100- Adjacent Owner Responsibility
a) It shall be the responsibility of a property owner, lessee, tenant, or occupant to trim or prune
and maintain all trees, shrubs, grass or other plantings now in existence or hereafter planted in
the public right-of-way of the property under such Person’s control unless otherwise agreed
upon by the City.
b) The failure of any property owner, tenant, lessee, or occupant to properly trim or prune trees,
shrubs, grass or other plantings, or to properly maintain the same, in the public right-of-way
or on the property frontage under their control in accordance with this Municipal Code, shall
be deemed a hazard to the public safety and a nuisance, and compliance may be obtained in
the same manner as a nuisance is provided for under the ordinances of the City.
c) If an obstruction persists, the City Manager shall notify the property owner to prune or remove
the tree or plant. If the owner fails to comply with the notice, the City may undertake the
necessary work and charge all applicable cost to the property owner.
11.47.110- Tree Stumps Prohibited
Any Tree Stump that is visible from the public right of way is hereby declared a public nuisance
and maintenance of a Tree Stump for more than 30 days is prohibited. Any Tree Stump shall be
ground down to a depth of four (4) inches below grade or the entire Tree Stump shall be removed
one year from the date of adoption of this ordinance and thereafter.
11.47.120- Costs for Tree Removal
All costs associated with the tree removal shall be at the expense of the property owner or
responsible party as determined by the City Manager. Any damages to the public right-of-way
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and/or to infrastructure as a result of removal of a tree shall be at the expense of the responsible
party.
11.47.130- Violation and Penalty
a) Each violation of this section as determined and notified by the City Manager shall constitute
a separate violation, punishable by fines and penalties under Chapter 1.06 (Community
Improvement and Administrative Citations), in addition to mitigation values placed on the
tree(s) removed or damaged in violation of this Chapter. Mitigation values shall be determined
by the City Manager after consultation with a certified arborist. Any fee charged by a certified
arborist pursuant to this section shall be added to the mitigation value assessment owed by the
violator.
b) The City may take Enforcement Actions, including the issuance of an administrative citation
and assessment of a fine, against Persons and entities for violating this chapter. The City’s
procedures on the imposition of administrative fines under Chapter 1.06 shall govern the
imposition, enforcement, collection and review of administrative citations issued to enforce
this chapter and any rule or regulation adopted pursuant to this chapter.
11.47.140- Procedures for Citations and Appeals
Prior to taking any Enforcement Action against a Person, business, or entity for violating this
Chapter, the City shall first notify the Person, business, or entity and provide an opportunity to
correct the violation through the issuance of a Notice of Violation by the Enforcement Officer.
Notices shall be sent to the owner at the official address of the owner maintained by the tax
collector for the City or if no such address is available, to the owner at the address of the residential
dwelling or commercial property, depending upon available information. This notice shall contain
information required by Palm Springs Municipal Code section 1.06.030 (b). The notice shall state
the Person, business, or entity has 60 days to correct the violation.
11.47.150- Local Government Disclaims Liability
Nothing contained in this section shall be interpreted to impose any liability upon the City, its
officers, employees, or agents, nor to relieve the owner of any private property from the duty to
keep any Tree, Shrub or plant located upon the adjacent Planting Strip or upon the owner’s private
property from becoming hazard or public nuisance.
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SECTION 3. Effective Date This Ordinance shall become effective on November 1, 2025.
SECTION 4. Severability If any section, subsection, subdivision, sentence, or clause, or phrase in
this Ordinance or any part thereof is for any reason held to be unconstitutional, invalid, or
ineffective by any court of competent jurisdictions, such decision shall not affect the validity or
effectiveness of the remaining portion of this Ordinance or any part thereof. The City Council
hereby declares that it would have adopted each section irrespective of the fact that any one or
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more subsections, subdivisions, sentences, clauses, or phrases are declared unconstitutional,
invalid, or ineffective.
SECTION 5. CEQA The proposed Municipal Code Amendment is exempt from the California
Environmental Quality Act (CEQA) pursuant to Section 15307 (Class 7) for actions taken by
regulatory agencies to protect natural resources, and Section 15308 (Class 8) for actions taken to
protect the environment. The amendment establishes public and private tree management
programs that will help preserve tree canopy, prevent unnecessary or improper removal of trees,
and promote sustainable urban forestry practices. These actions support the long-term protection
of natural resources and environmental quality. The amendment is also exempt under Section
15061(b)(3), the general rule exemption, because it can be seen with certainty that there is no
possibility the activity may have a significant effect on the environment.
SECTION 6. Publication The City Clerk shall certify to the adoption of this Ordinance and cause
it, or a summary of it, to be published in a newspaper of general circulation printed and published
within the City of Palm Springs, pursuant to all legal requirements.
ATTACHMENT B
Tr ee Maintenance
Guide
City of
Palm Springs
CONTENTS
Purpose ......................................................................................................................................... 3
Plant Health Care .......................................................................................................................... 3
Tree Inspections ........................................................................................................................ 3
Cultural Practices to Support Tree Health ................................................................................. 3
Water Management ............................................................................................................... 4
Mulching ................................................................................................................................ 5
Fertilization ............................................................................................................................ 6
Sanitation ............................................................................................................................... 7
Tree Removals .......................................................................................................................... 7
Pruning .......................................................................................................................................... 7
Structural Pruning for Young Trees ........................................................................................... 8
Pruning for Established Trees ................................................................................................... 9
Provide Clearance ................................................................................................................. 9
Maintain Health .................................................................................................................... 10
Reduce Density ................................................................................................................... 10
Canopy Restoration ............................................................................................................. 11
Size Management ................................................................................................................ 11
Palm Pruning ........................................................................................................................... 11
Integrated Pest Management ...................................................................................................... 12
Urban Forest Monitoring .......................................................................................................... 13
Pest/Disease Identification ...................................................................................................... 13
Cultural and Biological Pest Control ........................................................................................ 13
Chemical Control ..................................................................................................................... 14
Risk Assessment ......................................................................................................................... 14
Wildlife Protection ....................................................................................................................... 15
Tree Palette ................................................................................................................................. 17
Plant Characteristics Used ...................................................................................................... 17
Foliage Type ........................................................................................................................ 17
Maximum Height and Width ................................................................................................. 18
Water Usage ........................................................................................................................ 18
Pests and Diseases ............................................................................................................. 18
Tree Planting ............................................................................................................................... 32
Soil Testing .............................................................................................................................. 32
Species selection .................................................................................................................... 32
Nursery Stock Selection .......................................................................................................... 32
Tree Installation ....................................................................................................................... 35
New Tree Support and Trunk Protection ................................................................................. 36
Tree Stake Installation ......................................................................................................... 37
Tree Stake Inspection .......................................................................................................... 39
Tree Stake Removal ............................................................................................................ 39
Monitoring of Newly Planted Trees ...................................................................................... 39
Appendix A – Sources ................................................................................................................. 40
Appendix B – ANSI Standards and ISA BMP Links .................................................................... 41
Appendix C – Additional Tree Care Resources ........................................................................... 42
PURPOSE
The intent of this Tree Maintenance Guide is to provide tree management guidelines based on
current American National Standards Institute (ANSI) A300 Tree Care Standards and
International Society of Arboriculture (ISA) Best Management Practices to City staff, residents,
property owners, tree care professionals, and others providing urban forest services in the city
of Palm Springs.
PLANT HEALTH CARE
Plant health care is an integrated process that begins with appropriate species selection based
on the size and location of the planting site, selection of healthy nursery stock with good branch
and root structure, proper installation practices (planting and staking), and regular, systematic
maintenance (watering and structural pruning for young trees, regular pruning for established
trees). Appropriately selected trees with adequate growing conditions and proper maintenance
are more resilient to environmental stresses and have the necessary resources to resist or
tolerate many pests and diseases without additional treatment. As essential components of any
Plant Health Care (PHC) and Integrated Pest Management Program (IPM), species selection
(Tree Palette), nursery stock inspection (Nursery Stock Selection), installation practices, and
proper maintenance are discussed in greater detail in this maintenance plan. This section will
focus on standards for cultural care and pest and disease susceptibility, diagnostics and
standard treatment practices.
Tree Inspections
Regular inspection of trees is essential to maintaining a healthy urban forest. Prior to any
scheduled maintenance work, each tree should be inspected for structural defects, dead or
broken branches, and signs of stress, decline, pests, or disease. If any of these issues is
observed, the condition will be noted in the electronic inventory for the site and the tree will be
referred to the (City input needed for reporting channels) for additional inspection as needed. If
the tree is scheduled for pruning or a service request has been made for pruning, the inspector
will determine if pruning is required.
Cultural Practices to Support Tree Health
Planting the right tree in the right place according to the installation standards presented in the
Tree Planting section is the first step in the Plant Health Care Program. The establishment and
long-term health of the tree will depend on good cultural practices to maintain the tree’s growing
environment. Cultural care includes proper water management, mulching, fertilization,
sanitation, and pruning practices to establish environmental conditions around the tree that are
favorable for tree growth, while eliminating conditions that favor pests and diseases. The extent
to which these practices can be implemented may be limited in the urban setting by available
space, infrastructure needs, and development. There is a continuum for each of these practices
where too much and not enough can lead to stress for the tree, so each process needs to be
properly planned to respond to the needs of the tree to the extent possible in the urban
environment. The information presented in each section below is summarized from the ISA Best
Management Practices and ANSI A300 Tree Care Standards (Appendix B).
WATER MANAGEMENT
Access to adequate available water is essential for the growth and health of all trees. The
movement of water in a tree requires that the roots uptake enough water to balance that which
is lost through leaf transpiration in the canopy. Insufficient soil moisture reduces the ability of
roots to access and uptake water. If the roots are unable to uptake enough water to replace
transpiration losses, leaves and branches may begin to wilt and die back, beginning in the upper
canopy. Water stressed trees are also typically more susceptible to pests and disease as
resources needed to produce defensive chemicals become limited or reallocated.
Similarly, excessive soil moisture is problematic for the health of trees. Like all living cells, root
cells require oxygen to function and remain alive. Roots access both water and air stored in the
pore spaces between soil particles. As soil becomes oversaturated, the pore spaces become
filled by excess water, displacing air. Without the necessary air, root function is reduced and
eventually the roots begin to die. The resulting reduction in root system function and volume
reduces water uptake and can lead to similar symptoms as those expected in water stressed
trees.
Trees established in the landscape will have developed root systems connected to adequate
water sources and should only require supplemental water during long periods of drought for
non-irrigated sites, or if there are long-term changes to the frequency or duration of watering
cycles for irrigated sites.
Supplemental water is required for young, newly planted trees until they become established,
usually one to two years after installation. If an irrigation system is to be used to provide
supplemental water, the new trees should be on a dedicated valve and program, separate from
adjacent lawn or shrub systems. Soil moisture should be tested periodically using a soil probe to
make sure the soil is being kept moist but not oversaturated and the program should be
adjusted accordingly.
Sites without automatic irrigation will require hand watering of newly planted trees. A watering
schedule will need to be developed and the responsible party clearly defined for all new tree
plantings. To avoid overwatering, samples of the soil should be taken with a soil probe prior to
hand watering, with supplemental water provided only as required to maintain adequate soil
moisture. Water should be even distributed throughout the watering basin established at
installation (see Appendix B - Standards and Best Management Practices). Any disturbance to
the berm or basin will need to be repaired at the time of watering, or prior to watering at the next
scheduled visit.
The frequency of visits will be based on the specific needs of the species based on the water
usage provided in the species profile (Tree Palette). Table 1 provides a general schedule based
on time of year and species water usage. A general guidance for the volume of water to be
provided at each visit is ten (10) gallons of water for every one (1) caliper inch of the trunk.
Water Usage June - October November - May
Very Low 1x per week
1x per week (0 – 3 months
after installation)
Every other week (3 months
+ after installation)
Low
2x per week (0 – 3 months
after installation)
1x per week (3 months +
after installation)
1x per week
Moderate 2x per week 2x per week
Table 1: General Watering Schedule Based on Water Usage
MULCHING
There are many benefits of mulch application for trees in the urban forest. Mulches help:
• Maintain soil moisture;
• Manage weed growth;
• Moderate soil temperature changes;
• Reduce soil compaction and erosion;
• Increase soil organic matter which stimulates microbial activity, soil aggregation, and
nutrient availability.
Like all cultural practices, these benefits may not be realized if mulch is not applied in the proper
manner. In fact, improper mulch application can be more harmful to the health of the tree than
not applying mulch at all.
Figure 1 illustrates proper mulching technique and some potential consequences of improper
mulching. In general, mulch:
• Should cover as much of the root zone as possible.
o For newly planted trees, 1.5 to 3 inches diameter at breast height (DBH), mulch
should be applied over an area with a minimum 3-foot radius.
o For larger trees, it is ideal to apply mulch from near the trunk to the dripline,
however, the minimum radius of the mulched area should be three times the
DBH.
• Applied in a continuous bed around multiple trees.
• Should not be in contact with the trunk of the tree. The area six to eight inches (6” – 8”)
from the base of the trunk should be left clear of mulch when practical.
• Should be tapered in depth from a thin layer near the trunk to a maximum depth of two
inches (2”) near the edge of the mulched area.
More detailed information can be found in the Mulching Section of the ISA Best Management
Practices – Soil Management for Urban Trees.
Figure 1: Proper mulching techniques
FERTILIZATION
Fertilizers should only be applied to established trees when a nutrient deficiency is identified
through lab analysis of soil and tissue samples. Some pests and diseases can cause very
similar symptoms to those typically associated with nutrient deficiencies, so samples should
always be taken to confirm the deficiency before a fertilizer is applied. For new tree plantings,
adding organic amendments to the top six inches of backfill soil will improve soil structure while
promoting beneficial soil microbe development, and healthy root growth for the tree.
If specific nutrient deficiencies are identified in soil or tissue samples, a Certified Arborist or Pest
Control Advisor can provide an appropriate fertilizer treatment plan. Further information
regarding tree nutrient requirements and fertilizer application can be found in Appendix B in the
ISA BMP - Tree and Shrub Fertilization.
SANITATION
Sanitation practices refer to removal of broken, dead, diseased or pest infested branches from a
tree. Broken and dead branches can serve as sites for pest infestation or pathogen entry sites
into the tree. Removing branches infected by a pathogenic disease or infested with a bark or
stem boring pest can help to slow or even eliminate the spread of the pest or disease to other
parts of the tree. It is an important part of this process to remove pest infested or diseased
branches, twigs and foliage from the site and dispose of these parts according to recommended
protocols. An ISA Certified Arborist, Pest Control Advisor, County Agricultural Commissioner, or
the local office of the University of California Cooperative Extension Division of Agriculture and
Natural Resources (UCANR) can provide recommended disposal protocols.
Tree Removals
The removal of dead, dying, or hazardous trees is a necessary element to maintaining a healthy
and sustainable urban forest. As living organisms, trees have a finite lifespan and will eventually
begin to decline and expire. Trees planted in spaces too small for the species will eventually
outgrow the space and decline or damage the surrounding hardscape. Removal should be
considered as the final option, once other alternatives have been ruled out, for trees in the City
of Palm Springs. An ISA Certified Arborist shall inspect each tree proposed for removal and
provide a written report with recommendations to the (City input needed for reporting channels).
The arborist report will be attached to the tree site in the Electronic Inventory System. Approval
from the (City input needed for reporting channels) is required prior to any tree removal, with the
exception of trees that are removed as part of an emergency response.
The removal will be noted in the Electronic Inventory System once work is completed. To the
extent possible, the stumps of removed trees and all major roots should be removed by hand or
using a stump grinder. Replacement species should be selected from the Approved Tree Palette
based on the size of the available space and the desired form and function for the planting site.
Replacement with the same species or a species susceptible to the same disease is not
recommended if the tree was removed due to a soil-borne disease. (City input needed for
reporting channels) should consult with an ISA Certified Arborist during the tree selection
process to determine the appropriate replacement species in these cases.
PRUNING
Where practical pruning should be conducted according to ANSI A300 Tree Care Standards and
ISA Best Management Practices (Appendix B). Some general acceptable pruning guidelines
include:
• Define the objectives of the pruning;
• Remove only the amount of material necessary to meet the objectives;
• To the extent possible avoid cuts to large branches (branches with a diameter of four
inches [4”] or greater) that will create a large wound. Large wounds are more susceptible
to pests, disease, and decay;
• Avoid poor pruning practices such as flush cuts; topping, lion-tailing, excessive thinning,
excessive raising, or excessive reduction;
• Make cuts back to branch unions with the remaining branch at least one-third the
diameter of the branch to be removed, do not leave stubs;
• Use the three cut method (Figure 2) to preserve the branch collar and avoid bark tearing
to the trunk or remaining branch;
• Sanitize pruning equipment with an alcohol or bleach solution before moving to a
different tree, or making a cut on the same tree if disease or pest infestation is
suspected on the previously cut branch.
Figure 2: The Three Cut Method
(Graphic courtesy of the ISA Best Management Practices – Pruning, Third Edition. Cut 1 is an
undercut made one to two feet from the parent branch or trunk, Cut 2 is a top cut slightly further
out on the branch than Cut 1 (directly above when using a chain saw), and Cut 3 is the final cut
made just outside the branch collar.)
Structural Pruning for Young Trees
Structural pruning of young trees promotes healthy branch architecture, reduces the need for
excessive trimming, and reduces the number of large branch cuts as the tree matures. Figure 3
details the objectives of a structural pruning plan for young trees.
Figure 3: Structural pruning for young trees
Pruning for Established Trees
Pruning for mature and maturing trees should always be conducted to accomplish a clearly
defined objective. Potential pruning objectives include:
• Provide Clearance
• Maintain Health
• Reduce Density
• Canopy Restoration
• Size Management
PROVIDE CLEARANCE
In the urban environment, tree canopies can interfere with pedestrian walkways, infrastructure,
buildings, vehicle traffic, traffic signs and signals, lines-of-sight, overhead utility lines and other
site uses and activities. Clearance pruning of established trees may be necessary to reduce this
interference. To the extent possible, clearance pruning cuts to large diameter branches should
be avoided. To reduce the number of cuts to larger diameter branches, directional pruning of
branches to encourage growth away from the area of potential interference is preferred.
Directional pruning (Figure 4) involves:
• Reduction or removal of branches that are causing or have the potential to cause
interference,
• Making cuts back to a union with lateral branches that are growing in the direction of the
interference,
• Making all cuts to branch unions to avoid leaving branch stubs in the canopy,
• Avoiding topping cuts.
Figure 4: Clearance pruning
(Graphic courtesy of the ISA Best Management Practices – Pruning, Third Edition. Lower
branches are removed at the trunk [a-3] or reduced at branch unions [a-1, a-2, b-1, b-2].)
MAINTAIN HEALTH
Targeted pruning to remove pest infested, disease infected, damaged, or rubbing branches can
help to reduce the spread of pests and disease and maintain a healthy tree canopy.
Consultation with a licensed Pest Control Advisor regarding potential treatments when pruning
for pest infested branches, branches infected with disease pathogens, or when cuts to larger
diameter branches are required is recommended to reduce the spread of the target pest or
disease and reduce the likelihood of additional infestation or infection by opportunistic pests or
pathogens.
REDUCE DENSITY
Reducing canopy density (thinning) to increase light penetration and air flow through a mature
tree is often necessary to maintain tree health, stability, and aesthetics. The density reduction is
accomplished by:
• Selective removal of the longest and largest branches for young trees,
• Selective reduction of the longest and largest branches for mature and maturing trees,
• To the extent possible, reductions to the dominant leader should be avoided,
• Avoid removal of live interior and lower lateral branches (lion-tailing).
CANOPY RESTORATION
Canopy restoration is intended to improve tree structure resulting from topping, severe heading
cuts, vandalization, lion-tailing, or storm damage. Restoration is a process that typically requires
several pruning cycles to complete. Canopy restoration involves:
• Selective removal and/or reduction of branches, sprouts, and stubs to encourage a more
natural, structurally sound form,
• Selectively removing and/or reducing sprouts originating from the same point near the
end of branch stubs, while preserving some of the sprouts that will become permanent
branches in the restored canopy structure,
• To replace broken branches:
o Select two sprouts growing from the trunk or branch union that will become
permanent branches in the restored canopy,
o Remove or reduce other branches growing from the base of the pruned area
where the branch break occurs,
• Restoration for branches that have been lion-tailed can take one to several years,
depending on species, age, tree condition, and site conditions:
o Allow sprouts to develop undisturbed along the interior of the branch,
o After sprout growth rate has slowed, remove or reduce sprouts so that they are
evenly spaced and distributed along the entire length of the branch.
SIZE MANAGEMENT
The objective of size management pruning is to reduce the height or width of a tree due to
interference with desired objects or functions at the site, while maintaining the form and
structure of the tree. Size management pruning involves:
• Branch removal cuts,
• Reduction cuts,
• Heading cuts, only when no other option is available,
• To the extent possible cuts should be made to branches four inches (4”) or less.
Palm Pruning
Falling palm fronds, flowers, fruits, and dead petiole bases can pose a risk to people,
infrastructure, and other structures. To reduce this risk, palms must often be pruned annually or
biannually. Palms lack the secondary meristem tissue that allow for trunk expansion, secondary
branching, and compartmentalization of wounds. All frond growth, trunk expansion and vertical
growth occurs from a single apical meristem. When pruning palms (Figure 5):
• Do not remove live, healthy fronds except when required for clearance,
o If live fronds must be removed, avoid removing fronds with petioles attached
above the horizontal plane of the crown,
• Remove fronds as close as feasible to the petiole base without damaging the living
tissue in the trunk,
• Use the Three Cut Method (Figure 2) when removing larger fronds to avoid ripping the
trunk,
• Use hand saws, or a chainsaw designated only for the specific tree, when pruning
species infected or susceptible to Fusarium wilt,
o Hand saws should be sterilized, or have a new blade installed between pruning
of different trees to avoid spreading the Fusarium pathogen that causes wilt
disease
• Do not use climbing spikes to prune palms. Wounds from climbing spikes cannot be
compartmentalized by the palm and provide permanent openings for pathogens that can
lead to trunk rot,
• Remove frond skirts from the top down for worker safety.
Figure 5: Palm pruning
(Graphic courtesy of the ISA Best Management Practices – Pruning, Third Edition. The image to
the left shows a palm before pruning, the middle image illustrates an example of appropriate
pruning of this palm, the image to the right illustrates over pruning of this palm. Over pruning
can have significant impact on the future health of the palm.)
INTEGRATED PEST MANAGEMENT
The cultural practices above are an integral part of plant health care and the first step in an
Integrated Pest Management (IPM) Program. IPM is a combination of multiple practices for the
prevention and control of pests and disease. Proper cultural practices are focused on reducing
abiotic (non-living) factors that can impact the health of a tree. Healthy trees are better able to
tolerate and resist pests and are less susceptible to pathogenic disease. In addition to the
cultural practice standards, monitoring, biological control practices, tracking of emerging pests
and diseases, and chemical control can help maintain a healthy urban forest. Specific pest and
disease issues will apply this framework in consultation with a licensed California Department of
Pesticide Regulation Agricultural Pest Control Adviser (Pest Control Adviser).
Urban Forest Monitoring
Regular monitoring of the urban forest trees for early signs of abiotic stress, pests, and disease
is an important part of maintaining a healthy and sustainable urban forest in the City of Palm
Springs. The number of treatment options for most pests and diseases is greater, and usually
more effective when detected in the early stages. In addition to periodic urban forest monitoring,
tree crews should inspect each tree prior to starting pruning work and continue to look for signs
of pests or disease as the work progresses.
Trees identified with any signs or symptoms of stress, pests or disease will be noted in The
City’s Electronic Inventory System for follow up inspections to identify the cause and determine
the appropriate treatment plan.
Pest/Disease Identification
Proper identification of the abiotic factor, pest, or disease that is causing the observed
symptoms is a key part of Integrated Pest Management. When no direct signs of known pests or
disease are observed at the time of inspection, the inspector should photograph the symptoms
and signs and collect samples for submittal to a qualified laboratory for identification.
Cultural and Biological Pest Control
Most pathogenic fungi and bacteria tend to thrive in moist, cool conditions. Over irrigated soils
can provide a favorable environment for pathogens that cause root rot. Excessive moisture at
the base of a tree due to a buried root flare or an irrigation head directed at the trunk can
promote conditions favorable to many vascular and rot diseases. Dense foliage growth provides
shelter for insect pests and reduces air flow which can lead to increased moisture retention in
the inner canopy and create favorable conditions for casual agents of branch and leaf diseases.
Flushes of new growth resulting from unnecessary or inappropriately timed fertilizer application
can attract and promote population growth for many insect pests. Eliminating favorable
environmental conditions for growth, reproduction and spread can maintain many pests and
diseases at tolerable levels in the urban forest.
In addition to cultural controls, some insects can be effective in the control of pest populations
as natural predators and parasitoids. There are three biological control implementation
approaches:
• Conservation
• Augmentation
• Introduction
The conservation approach focuses on maintaining an environment that promotes existing
beneficial insects by:
• Avoidance of broad-spectrum pesticides in favor of products that kill only targeted pest
• Timing applications to reduce the impacts to beneficial insects
Augmentation involves the release of native and naturalized beneficial insects to supplement
existing populations. Many common natural predators are commercially available for purchase
as part of an augmentation program. Augmentation of existing beneficial insect populations
should be considered on a case-by-case basis in consultation with a licensed Pest Control
Advisor.
The introduction approach is a highly regulated process of releasing non-native predatory
species, and it is usually reserved for introduced pest species that lack native or naturalized
predators. Before a non-native predator can be considered for release, it undergoes years of
testing under government agency supervision to ensure the potential predator will not have
adverse impacts on the native ecosystem. The introduction approach is beyond the scope of the
this Maintenance Plan.
Chemical Control
The goal of IPM programs is to reduce the use of pesticides, especially broad-spectrum
pesticides, to control pests and diseases within the urban forest to the extent possible by
selecting the appropriate species for the planting site (Tree Palette), following the proper BMPs
and Standards for installation, and applying the above mentioned monitoring, cultural and
biological control practices. Under IPM, chemical control is the last option when control of a pest
or disease cannot be achieved by other methods. Before initiating chemical control, consult with
a licensed Pest Control Advisor to develop a treatment plan and obtain a written Pesticide
Recommendation.
RISK ASSESSMENT
Despite proper management to maintain a healthy urban forest that maximizes the benefits to
the community, there are risks to persons and property associated with trees. Trees are living
organisms and the potential for failure, either in entirety or in part, cannot always be predicted.
The goal for urban forest managers is to find a balance where the benefits provided are greater
than the risks associated with the trees.
The ISA has developed the Tree Risk Assessment Qualification (TRAQ) to train arborists to
evaluate this risk to the greatest extent possible. Risk assessment ratings can assist City of
Palm Springs in prioritizing maintenance needs and scheduling.
TRAQ designates three levels for conducting risk assessments based on the level of detail
required.
Level 1 Limited Visual Assessment: a tree or tree population is observed from one
perspective to identify obvious defects or conditions with increased likelihood of failure near
specified targets. Level 1 Risk Assessments can also be conducted from a slow-moving vehicle
or aerially using an unmanned aerial vehicle (drone).
Level 2 Basic Assessment: a 360° ground based visual inspection of the subject tree(s) and
the surrounding site. The visible buttress roots, trunk and branches are inspected for defects
and each defect is evaluated for likelihood of failure. The likelihood of failure is combined
according to a matrix with the likelihood of the failed part contacting each of the identified
targets to determine an overall likelihood a particular target will be struck. Occupancy rate and
distance of the target from the tree are factored into this determination. The likelihood of failure
and impact are combined in a separate matrix with the consequences of impact on the target to
assign a risk rating for the tree or tree part.
Level 3 Advanced Assessment: advanced assessment to obtain more detailed information
about specific tree parts, defects, targets, or site conditions during or after a Level 2 Basic
Assessment using specialized equipment, analysis, and/or expertise.
WILDLIFE PROTECTION
In addition to the benefits for people, the urban forest also provides habitat for a great number of
wildlife species. Trees can serve as valuable sites for roosting, foraging, shelter, and nesting,
attracting many wildlife species that would otherwise not be found in urban environments.
Interactions with many of these wildlife species, such as resident and migrating birds, add to the
beauty and quality of life for the residents of the community.
Many of the tree maintenance activities included in this Maintenance Plan may impact and/or
cause harm to wildlife and measures to protect wildlife are a key component to the Urban Forest
Operations Plan. In addition to the community benefits they provide; Federal and State of
California laws require measures to protect wildlife in the urban forest including:
• Federal Migratory Bird Treaty Act (MBTA)
• Federal Endangered Species Act (ESA)
• Federal Bald and Golden Eagle Protection Act (BGEPA)
• California Endangered Species Act (CESA)
• California Fish and Game Code Sections 3500-3513
• California Fish and Game Code Sections 1600-1617
The degree to which tree maintenance activities impact wildlife will vary based on the time of
year and the habitat value associated with the species of tree(s) where maintenance work will
be performed. Wildlife can nest at any time during the year and in any tree regardless of habitat
value, however, the likelihood of activity is much higher during the breeding season for the
wildlife species in trees with higher habitat value. Table 2 provides the breeding periods for
selected groups of birds as a general guideline.
To assist urban forest managers in deciding the level of protection measures required, the ISA
Tree Care for Wildlife Best Management Practices (Appendix B) suggests three categories
determined by the breeding season for the species, or group of species of concern and the
habitat value provided by the tree(s) that require maintenance activities. The three categories
are defined according to the matrix in Table 3.
To protect wildlife during tree maintenance activities:
For Work to be performed in Category 1 Wildlife Protection Areas:
• Crews should be trained by a Wildlife Trained Arborist or Wildlife Biologist to conduct
pre-work inspections for signs of nesting wildlife,
• The training can be site specific or general wildlife awareness training for city-wide work,
• Trained crews will conduct a pre-work survey for wildlife prior to beginning work.
For Work to be performed in Category 2 Wildlife Protection Areas:
• Pre-work inspection should be conducted by a Wildlife Trained Arborist.
For Work to be performed in Category 3 Wildlife Protection Areas:
• Pre-work inspection should be conducted by a Wildlife Biologist or Wildlife Trained
Arborist specifically trained by a Wildlife Biologist for High Habitat Value areas in the City
of Palm Springs.
If signs of wildlife nesting activity are observed:
• The scheduled work should be delayed until the nesting activity has concluded, and the
young have left the nest as determined by a Wildlife Trained Arborist or Wildlife
Biologist.
• An appropriate buffer, according to Table 2 or at the direction of a Wildlife Biologist,
should be established around the nest. Maintenance work should be delayed for any
scheduled trees that fall within the buffer area or would require crews or equipment to
enter the buffer area to conduct the scheduled work.
• Signs should be posted on the nesting tree and any additional tree in the buffer area to
provide public notice of the delay in work.
• A note will be attached in the City’s electronic inventory system to the nesting tree site
and any tree sites within the buffer zone detailing the wildlife nesting and the delay in the
maintenance work.
Bird Group Typical Breeding
Season
Egg
Incubation
Period
(Days)
Duration of
Period from
Hatching to
Young Leaving
the Nest
Minimum
Buffer Radius
for Low
Habitat Value
Trees (feet)
Minimum
Buffer Radius
for High
Habitat Value
Trees (feet)
Herons and Egrets January – August 19 – 27 21 – 81 days 200 300
Birds of Prey
(Hawks, Vultures,
Falcons)
February - August 25 – 36 4 – 7 weeks 300 500
Doves February - November 14 – 20 13 – 30 days 100 300
Owls January – July 26 – 35 28 – 60 days 300 500
Hummingbirds December - July 13 – 18 20 – 23 days 100 300
Songbirds (eg.
Finches, kingbirds,
mockingbirds)
February - August 11 – 17 9 – 25 days 100 300
Crows, Ravens,
Jays February - August 15 – 21 Jays: 18 days
Crows: 35 days 100 300
Ravens: 5 – 6
weeks
Table 2: Breeding Season, Incubation Period, Fledging Duration, and Buffer
Requirements for Selected Groups of Birds
Table 3: Wildlife Protection Categories
(From the ISA Tree Care for Wildlife Best Management Practices)
TREE PALETTE
Installing the wrong tree species for the site can lead to increased maintenance efforts and cost,
increased water usage, damage to infrastructure, conflicts with overhead utilities, lighting, traffic
signs and signals, and may even result in the death of the tree. The need to conserve water
resources, due to changes in climate and sustained drought, must also be a major consideration
in species selection for a healthy and sustainable urban forest. Tables 4 – 9 below list the
appropriate tree species based on the size of the planting area, proximity to overhead utility
lines, and water usage. Trees that are native to Southern California are marked with an asterisk
symbol (*).
Plant Characteristics Used
FOLIAGE TYPE
This characteristic describes the persistence of leaves on trees of a given species. The three
categories for foliage type are evergreen, deciduous and partly deciduous.
Evergreen (E) – Trees that do not lose all their leaves or needles at any one time. These trees
will drop older leaves at specific times or throughout the year depending on the species.
Evergreen trees remain green throughout the winter.
Deciduous (D) – Trees that lose their leaves completely and enter a period of dormancy in a
given season. Most species are fall or winter deciduous and will become dormant during the
colder periods of the year; however, there are a handful of drought deciduous species that will
enter dormancy during the summer when temperatures are higher and water is less available.
Partly Deciduous (PD) – Trees that lose most of their leaves during the dormancy period, while
still retaining some living foliage at lower densities.
Some tree species can adapt foliage type depending on climate and local weather patterns. For
example, if the winter temperatures in a given area are mild and rarely below freezing, a species
that is normally deciduous may adopt a partly deciduous foliage type in that area. Species that
demonstrate this adaptive characteristic are indicated in the tables below with a range for the
foliage type.
MAXIMUM HEIGHT AND WIDTH
The numbers for maximum height and width presented in the tables that follow represent the
observed values, in feet, for trees of each species from the available literature. Environmental
factors such as availability of growing space, light, and water may limit growth preventing
individual trees from reaching these dimensions.
WATER USAGE
The water usage rating given for each tree species in the tables and species profiles below is
based on the Water Use Classification of Landscape Species (WUCOLS) values. WUCOLS
rates the water usage by species according to four categories, Very Low, Low, Moderate, High.
For species that have not been evaluated as part of WUCOLS, water usage rates were based
on the values presented in the SelecTree databases using the same scale values.
Very Low – Once established, species with a Very Low rating do not require irrigation water to
supplement normal precipitation, except in years with below average rainfall.
Low – Once established, species with a Low rating require only minimal irrigation water during
the summer months.
Moderate – Once established, species with a Moderate rating require irrigation water to remain
healthy, especially during the summer and during long periods without precipitation.
High – Species with a High rating require regular irrigation to remain healthy, especially during
the summer.
PESTS AND DISEASES
Pest and disease susceptibility presented in the Tables 4 – 9 are based on available literature
for each species and are not an all-inclusive list. The pests and diseases listed are intended as
a guide. Trees may be impacted by other known and emerging pests and diseases not listed
here .
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Minimum
Planter
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Mulga Acacia aneura Australia E 20 20 2 – 4 24 Low Yes Low Root Rot Armillaria Invasive Shot Hole Borer
Bailey acacia Acacia baileyana Southern Australia E 30 40 4 – 7 36 Moderate No Low Phytophthora Armillaria
Root Rot
Invasive Shot Hole Borer
Thrips
Purple-leaf acacia Acacia baileyana
‘Purpurea’ Eastern Australia E 30 30 4 – 7 36 Moderate Yes Very Low Phytophthora Armillaria Invasive Shot Hole Borer
Thrips
Weeping acacia Acacia pendula Eastern Australia E 30 20 2 – 4 24 Moderate No Moderate Root Rot Armillaria Invasive Shot Hole Borer
Caterpillars
Willow acacia Acacia salicina Australia E 40 15 4 – 7 36 Low Yes Low Root Rot Armillaria Invasive Shot Hole Borer
Shoestring acacia Acacia stenophylla Australia E 30 20 4 - 7 36 Low Yes Very Low Armillaria
Root Rot Invasive Shot Hole Borer
Mimosa Albizia julibrissin Southwestern and
Eastern Asia PD 35 20 4 – 7 36 Moderate No Moderate
Armillaria
Fusarium
Root Rot
Invasive Shot Hole Borer
Caterpillars
Tree aloe Aloe barberae South Africa E 30 20 2 – 4 12 Moderate No Low Mites
Mealybugs
Strawberry tree Arbutus unedo Western Europe E 35 35 4 – 7 12 – 24 Low No Moderate
Anthracnose
Phytophthora
Root Rot
Rust
Scales
Thrips
King palm Archontophoenix
cunninghamiana Australia E 70 15 4 – 7 24 Moderate No Moderate Phytophthora
Root Rot Texas Root Rot
Invasive Shot Hole Borer
Scale
Mealybugs
Purple orchid tree Bauhinia variegata Asia PD 35 35 4 – 7 12 – 24 Low No Moderate Aphids
Hong Kong orchid tree Bauhinia x blakeana China PD 40 25 4 – 7 12 – 24 Low No Moderate Leaf Spot Aphids
Chinese Rose Beetles
Bottle palm Beaucarnea recurvata Eastern Mexico E 20 12 2 – 4 12 – 24 Low Yes Low Root Rot
Bottle tree Brachychiton populneus Eastern Australia E 50 30 > 7 24 Moderate No Moderate Root Rot Armillaria Invasive Shot Hole Borer
Queensland bottle tree Brachychiton rupestris Northeast Australia PD 35 30 > 7 24 – 36 Moderate No Moderate Root Rot
Mexican blue palm Brahea armata Baja California E 50 25 4 – 7 12 – 24 Low No Low Crown Rot Texas Root Rot Red Palm Weevil
Guadalupe palm Brahea edulis Guadalupe Island
(Mexico) E 25 15 4 – 7 12 Low No Low Texas Root Rot
Pindo palm Butia odorata Brazil E 25 12 4 – 7 12 – 24 Low Yes Low Root Rot Scales
Lemon bottlebrush Callistemon citrinus Southeastern Australia E 25 25 4 – 7 36 Low No Low Chlorosis Armillaria
Root Rot
Weeping bottlebrush Callistemon viminalis Australia E 20 20 2 – 4 36 Low Yes Low Armillaria
Root Rot
Floss silk tree Ceiba speciosa Central South America PD 60 50 > 7 12 – 24 Moderate No Low
Purple leaf eastern redbud Cercis canadensis
‘Forest Pansy’ Eastern United States D 30 25 4 – 7 24 Low No Moderate
Anthracnose
Crown Rot
Armillaria
Phytophthora
Caterpillars
Western redbud* Cercis occidentalis Western United States D 20 20 2 – 4 24 – 36 Low Yes Moderate
Crown Rot
Phytophthora
Root Rot
Caterpillars
Scales
Mediterranean fan palm Chamaerops humilis Western and Central
Mediterranean E 15 15 2 – 4 12 Low Yes Low Texas Root Rot
Desert willow* Chilopsis linearis
Southwestern United
States, Northern
Mexico
D 30 20 2 – 4 24 – 36 Low No Very Low Root Rot Texas Root Rot
Camphor tree Cinnamomum camphora China and Japan E 65 60 > 7 24 High No Moderate
Anthracnose
Armillaria
Phytophthora
Root Rot
Ghost gum Corymbia aparrerinja New Guinea, Northern
Australia E 50 35 4 – 7 36 Moderate No Very Low Armillaria
Root Rot
Texas Root Rot
Verticillium Beetle Borers
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Minimum
Planter
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Red flowering gum Corymbia ficifolia Western Australia E 45 60 4 – 7 24 Moderate No Low
Armillaria
Phytophthora
Root Rot
Texas Root Rot
Verticillium
Invasive Shot Hole Borer
Beetle Borers
Thrips
Smoke tree Cotinus coggygria Southern Europe,
Central Asia D 15 18 2 – 4 24 Low Yes Low Root Rot
Verticillium Armillaria
Purpureus smoke tree Cotinus coggygria
‘Purpureus’
Southern Europe,
Central Asia D 15 15 2 – 4 12 – 24 Low Yes Low
Leaf spot
Canker
Scab
Verticillium
Leaf Rollers
Indian rosewood Dalbergia sissoo India, Southern Iran D – PD 60 40 > 7 24 - 36 Moderate No Very Low
Root Rot
Butt Rot
Fusarium
Rust
Powdery Mildew
Termites
Defoliators
Sissoo Leaf Webber
Hopbush Dodonaea viscosa
Subtropical, warm
temperate Africa,
North America,
Central America,
South America,
southern Asia,
Australasia
E 15 15 2 – 4 24 – 36 Low Yes Moderate Phytophthora
Root Rot Scales
Purple hopbush Dodonaea viscosa
‘Purpurea’
Subtropical, warm
temperate Africa,
North America,
Central America,
South America,
southern Asia,
Australasia
E 30 20 4 – 7 24 Low No Moderate Phytophthora
Root Rot Scales
Texas ebony Ebenopsis ebano Southern Texas,
Eastern Mexico E 40 40 2 – 4 12 – 36 High No Low
Bronze loquat Eriobotrya deflexa Southeastern Asia E 25 25 4 – 7 36 Low Yes Moderate
Fire Blight
Entosporium Leaf
Spot
Mexican bird of paradise Erythrostemon
mexicanus Northern Mexico E 25 20 4 – 7 24 Low Yes Low Armillaria
Root Rot
Argyle apple Eucalyptus cinerea Southeastern Australia E 50 40 > 7 36 Moderate No Moderate Armillaria
Root Rot
Texas Root Rot
Verticillium Beetle Borers
Round-leafed moort Eucalyptus platypus Southern Australia E 35 35 4 – 7 36 Low No Very Low
Armillaria
Phytophthora
Root Rot
Texas Root Rot
Verticillium Beetle Borers
Orange gum Eucalyptus prava Northeast Australia E 30 30 2 – 4 24 – 36 Moderate No Low
Indian tree spurge / firestick Euphorbia tirucalli Tropical and Southern
Africa, Indonesia E 20 6 2 – 4 24 Low No Very Low
Peepul tree Ficus religiosa India, Southeast Asia E 100 100 > 7 24 Moderate No Moderate Armillaria
Root rot Scales
Shamel ash Fraxinus uhdei Central Mexico,
Central America PD – E 80 60 > 7 36 High No Moderate
Fusarium
Root rot
Sooty Mold
Verticillium
Armillaria
Aphids
Scales
Whitefly
Velvet ash* Fraxinus velutina Southwestern United
States, Mexico D 50 40 > 7 24 High No Moderate
Anthracnose
Mistletoe
Root Rot
Rust
Beetle Borers
Spider Mites
Whitefly
Modesto ash Fraxinus velutina
‘Modesto’
Southwestern United
States, Mexico D 50 40 > 7 36 High No Moderate
Anthracnose
Mistletoe
Root rot
Armillaria
Powdery Mildew
Rust
Beetle Borers
Psyllid
Spider Mites
Whitefly
Australian willow Geijera parviflora Eastern Australia E 35 20 4 – 7 24 – 36 Low No Moderate Armillaria
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Minimum
Planter
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Thornless honey locust Gleditsia triacanthos var.
inermis
Central and Eastern
United States D 60 40 > 7 36 Moderate No Moderate
Mistletoe
Phytophthora
Root rot
Verticillium
Invasive Shot Hole Borer
Caterpillars
Insect Galls
Pod Gall Midge
Silk oak Grevillea robusta Southeastern Australia E 65 60 > 7 36 Moderate No Low Phytophthora
Root Rot Scales
Sweet hakea Hakea drupacea Southwestern
Australia E 20 20 2 – 4 36 Low Yes Very Low Phytophthora
Root Rot
Golden trumpet tree Handroanthus
chrysotrichus
Eastern South
America D – PD 30 30 2 – 4 36 Moderate No Moderate
Jacaranda Jacaranda mimosifolia South-Central South
America PD 50 30 4 – 7 36 Moderate No Moderate Phytophthora
Root Rot Oak Root Fungus Invasive Shot Hole Borer
Aphids
Chilean wine palm Jubaea chilensis Chile E 80 25 > 7 12 Moderate No Low Texas Root Rot
Hollywood juniper Juniperus chinensis
‘Torulosa’ Northeastern Asia E 15 10 2 – 4 24 Low Yes Moderate
Armillaria
Root Rot
Rust
Texas Root Rot Beetle Borers
Spider Mites
Crape myrtle Lagerstroemia indica
Indian subcontinent,
Southeast Asia,
China, Korea, Japan
D 25 25 2 – 4 24 Low Yes Low Powdery Mildew
Sooty Mold Texas Root Rot Aphids
Cherokee crape myrtle Lagerstroemia indica
‘Cherokee’ Cultivar D 15 15 2 – 4 24 Low Yes Very Low Sooty Mold Powdery Mildew
Texas Root Rot Aphids
Glossy privet Ligustrum lucidum Southern China E 50 30 > 7 36 Moderate No Moderate
Armillaria
Phytophthora
Root Rot
Sooty Mold
Aphids
Leaf Miner
Feather bush Lysiloma watsonii Arizona PD – E 15 15 2 – 4 24 Low Yes Low Texas Root Rot
Palo blanco* Mariosousa heterophylla Mexico, Sonoran
Desert PD – E 20 15 2 – 4 12 - 24 Moderate Yes Low Invasive Shot Hole Borer
Flaxleaf paperbark Melaleuca linariifolia Eastern Australia E 30 25 4 – 7 36 Low No Low
Chlorosis
Phytophthora
Root Rot
Pink melaleuca Melaleuca nesophila Western Australia E 30 30 4 – 7 36 Low No Low Phytophthora
Root Rot
Cajeput tree Melaleuca quinquenervia Pacific Islands,
Eastern Australia E 40 25 4 - 7 24 Low No Low Phytophthora
Root Rot
Chinaberry Melia azedarach Asia D 50 25 > 7 36 Moderate No Low Scales
Olive Olea europaea Mediterranean E 30 30 4 – 7 12 – 24 Moderate No Low
Anthracnose
Armillaria
Phytophthora
Root Rot
Texas Root Rot Scales
Psyllid
Swan Hill olive (fruitless) Olea europaea ‘Swan
Hill’ Mediterranean E 30 30 4 – 7 24 Moderate No Low
Anthracnose
Armillaria
Phytophthora
Root Rot
Texas Root Rot Scales
Psyllid
Desert ironwood* Olneya tesota
Northwest Mexico,
Southeast California,
Western and Southern
Arizona, Colorado
Desert, Sonoran
Desert
E 30 30 4 – 7 12 Low No Low
Jerusalem thorn Parkinsonia aculeata
Western Texas,
Southern New Mexico,
Southern Arizona,
Mexico, Galapagos
Islands
D 20 25 2 – 4 24 – 36 Low Yes Low Texas Root Rot Invasive Shot Hole Borer
Blue palo verde Parkinsonia florida
Western Texas,
Southern New Mexico,
Southern Arizona,
Mexico, Galapagos
Islands
D 25 20 4 – 7 36 Low Yes Low Invasive Shot Hole Borer
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Minimum
Planter
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Littleleaf palo verde* Parkinsonia microphylla
Southeastern
California, Southern
Arizona, Northwest
Mexico
D 20 20 2 – 4 36 Low Yes Low
Borers
Caterpillars
Spider Mites
Palo brea* Parkinsonia praecox Sonoran desert D 20 20 2 – 4 36 Low No Low
Borers
Caterpillars
Spider Mites
Desert Museum palo verde Parkinsonia x ‘Desert
Museum’ Cultivar D 20 25 2 – 4 24 – 36 Low Yes Very Low Texas Root Rot Invasive Shot Hole Borer
Eriophyid Mite
Canary Island date palm Phoenix canariensis Canary Islands E 60 40 4 – 7 12 – 24 Moderate No Low Fusarium
Root rot Texas Root Rot
Date palm Phoenix dactylifera
Egypt, Iraq, Kuwait,
eastern Syria,
Southeastern Turkey
E 100 40 > 7 12 – 36 Moderate No Low Texas Root Rot
Senegal date palm Phoenix reclinata Tropical Africa E 35 20 4 – 7 12 – 36 Low No Moderate Leaf Spot Scales
Pygmy date palm Phoenix roebelenii Southeastern Asia E 15 7 2 – 4 12 – 24 Low Yes Moderate Leaf Spot Scales
Chinese photinia Photinia serrulata Southeastern Asia E 40 30 4 – 7 36 Low No Low
Armillaria
Powdery Mildew
Sooty Mold
Aphids
Scales
Fraser photinia Photinia x fraseri Asia E 20 12 2 – 4 24 – 36 Low Yes Moderate
Sooty Mold
Entosporium Leaf
Spot
Mildew Aphids
Red push pistache Pistacia x ‘Red Push’ Cultivar D 40 40 4 – 7 12 – 24 Low No Moderate Verticillium
Chinese pistache Pistacia chinensis China, Philippines D 35 35 4 – 7 24 Low No Low Verticillium
Root Rot Armillaria
Roberts’ Western sycamore Platanus racemosa
‘Roberts’ Cultivar D 50 50 > 7 36 Moderate No Moderate
Armillaria
Phytophthora
Mistletoe
Anthracnose
Invasive Shot Hole Borer
Leaf Miner
Scales
Spider Mites
Columbia planetree Platanus x hispanica
‘Columbia’ Cultivar D 80 40 4 – 7 36 Moderate No Moderate
Verticillium
Mildew
Anthracnose
Yew pine Podocarpus
macrophyllus
Southern Japan,
Southeastern China E 30 20 2 – 4 24 Low No Moderate Sooty Mold Mites
Scales
Chilean mesquite Prosopis chilensis South America D 30 30 4 – 7 36 Low No Low
Scales
Borers
Mealybugs
Stem Gall Rust
Honey mesquite* Prosopis glandulosa Southwestern United
States D 35 35 4 – 7 12 – 36 Low No Low
Scales
Borers
Mealybugs
Velvet mesquite Prosopis velutina Arizona, Texas,
Mexico D 30 30 4 – 7 24 Low No Low
Scales
Borers
Mealybugs
Carolina laurel cherry Prunus caroliniana Southeastern United
States E 30 25 4 – 7 36 Low No Moderate
Armillaria
Fire Blight
Root rot
Rust
Scales
Bright n Tight cherry laurel Prunus caroliniana
‘Bright n Tight’ Cultivar E 35 25 4 – 7 12 – 36 Low No Moderate
Armillaria
Leaf Spot
Fire Blight
Canker
Mites
Borer
Caterpillars
Hollyleaf cherry* Prunus ilicifolia California, Northern
Baja California E 30 25 4 – 7 24 Low No Low
Armillaria
Root rot
Rust
Sooty Mold
Whitefly
Aphids
Caterpillars
Catalina cherry* Prunus ilicifolia ssp.
lyonii Channel Islands E 35 30 4 – 7 24 Low No Low
Root rot
Rust
Verticillium
Virus
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Minimum
Planter
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Evergreen pear Pyrus kawakamii China, Taiwan PD – E 30 30 4 – 7 24 – 36 Low No Moderate Fire Blight
Sooty Mold Verticillium Aphids
Whitefly
Chisos oak Quercus canbyi Texas, Mexico PD – E 50 50 > 7 24 Low No Low
Armillaria
Anthracnose
Root Rot
Scales
Spider Mites
Netleaf oak Quercus rugosa
Mexico, Guatemala,
Arizona, New Mexico,
Western Texas
E 60 40 > 7 36 Moderate No Moderate Root Rot
Powdery Mildew
Sooty Mold
Sudden Oak
Death
Verticillium
Scales
Spider Mites
Spittlebugs
Aphids
Mistletoe
Island oak Quercus tomentella Channel Islands E 50 40 > 7 24 Moderate No Low Armillaria Verticillium
Sky Climber live oak Quercus virginiana ‘Sky
Climber’
Southern United
States PD – E 80 100 > 7 24 – 36 Moderate No Moderate
Armillaria
Phytophthora
Root Rot
Verticillium Insect Galls
Soapbark tree Quillaja saponaria Chile E 45 25 4 – 7 12 Low No Low
African sumac Searsia lancea South Africa E 30 35 4 – 7 24 Low No Very Low Root rot
Verticillium
Queen palm Syagrus romanzoffiana Southern Brazil,
Northern Argentina E 50 30 4 – 7 24 – 36 Moderate No Moderate
Butt Rot
Armillaria
Root Rot
Texas Root Rot Scales
Spider Mites
Montezuma cypress Taxodium mucronatum Mexico, Guatemala PD – E 80 40 > 7 36 Moderate No Moderate Beetle Borers
Leaf Beetles
Yellow bells Tecoma stans North America,
Central America E 25 20 4 – 7 36 Low Yes Moderate
Tipu tree Tipuana tipu Bolivia, Southern
Brazil D – PD 50 50 > 7 24 – 36 High No Moderate
Chinese tallow Triadica sebifera Eastern China, Taiwan D 40 30 4 – 7 24 – 36 Moderate No Moderate Armillaria
Drake Chinese elm Ulmus parvifolia ‘Drake’ China, Japan, North
Korea, Vietnam PD - E 45 50 4 – 7 36 Moderate No Moderate
Dutch Elm Disease
Armillaria
Phytophthora
Root Rot
Aphids
Beetle Borers
Leaf Beetles
Caterpillars
Sweet acacia Vachellia farnesiana Mexico, Central
America D - PD 25 25 4 – 7 24 – 36 Low Yes Very Low Root Rot Texas Root Rot Invasive Shot Hole Borer
Caterpillars
Chaste tree Vitex agnus-castus Mediterranean D 15 20 2 – 4 24 Low Yes Low Armillaria
California fan palm*‡ Washingtonia filifera
Southwestern
California, Baja
California
E 70 20 4 – 7 36 Moderate No Low Armillaria Texas Root Rot Red Palm Weevil
Mexican fan palm‡ Washingtonia robusta
Western Sonora
(Mexico), Baja
California Sur
E 100 10 4 – 7 36 Moderate No Low Texas Root Rot Beetle Borers
Red Palm Weevil
Chitalpa x Chitalpa tashkentensis Cultivar D 35 30 4 – 7 36 Low No Low Root Rot
Verticillium Aphids
Pink Dawn chitalpa x Chitalpa tashkentensis
‘Pink Dawn’ Cultivar D 35 25 4 – 7 36 Low No Low Root Rot
Verticillium Aphids
Majestic Beauty Indian
hawthorn
x Rhaphiobotrya
splendens ‘Montic’ Cultivar E 25 10 4 – 7 24 Low Yes Moderate
Fire Blight
Root Rot
Verticillium
Entosporium Leaf
Spot
Aphids
Shiny xylosma Xylosma congesta China E 10 15 2 – 4 24 Low No Low Chlorosis
Invasive Shot Hole Borer
Giant Whitefly
Scales
Spider Mites
Table 4: Overall Approved List of Species (* indicates species native to the Southern California region, ‡ indicates species that should only be considered for replacement of like species and not be installed
in new planting spaces)
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Golden trumpet tree Handroanthus
chrysotrichus Eastern South America D – PD 30 30 36 Moderate No Moderate
Indian tree spurge / firestick Euphorbia tirucalli Tropical and Southern
Africa, Indonesia E 20 6 24 Low No Very Low
Orange gum Eucalyptus prava Northeast Australia E 30 30 24 – 36 Moderate No Low
Palo brea* Parkinsonia praecox Sonoran desert D 20 20 36 Low No Low
Borers
Caterpillars
Spider Mites
Shiny xylosma Xylosma congesta China E 10 15 24 Low No Low Chlorosis
Invasive Shot Hole Borer
Giant Whitefly
Scales
Spider Mites
Texas ebony Ebenopsis ebano Southern Texas,
Eastern Mexico E 40 40 12 – 36 High No Low
Tree aloe Aloe barberae South Africa E 30 20 12 Moderate No Low Mites
Mealybugs
Weeping acacia Acacia pendula Eastern Australia E 30 20 24 Moderate No Moderate Root Rot Armillaria Invasive Shot Hole Borer
Caterpillars
Desert willow* Chilopsis linearis
Southwestern United
States, Northern
Mexico
D 30 20 24 – 36 Low No Very Low Root Rot Texas Root Rot
Yew pine Podocarpus
macrophyllus
Southern Japan,
Southeastern China E 30 20 24 Low No Moderate Sooty Mold Mites
Scales
Table 5: Approved List of Species for Planters 2’ – 4’ in Minimum Width with No Overhead Utilities (* indicates species native to the Southern California region).
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Bottle palm Beaucarnea recurvata Eastern Mexico E 20 12 12 – 24 Low Yes Low Root Rot
Chaste tree Vitex agnus-castus Mediterranean D 15 20 24 Low Yes Low Armillaria
Cherokee crape myrtle Lagerstroemia indica
‘Cherokee’ Cultivar D 15 15 24 Low Yes Very Low Sooty Mold Powdery Mildew
Texas Root Rot Aphids
Crape myrtle Lagerstroemia indica
Indian subcontinent,
Southeast Asia, China,
Korea, Japan
D 25 25 24 Low Yes Low Powdery Mildew
Sooty Mold Texas Root Rot Aphids
Desert Museum palo verde Parkinsonia x ‘Desert
Museum’ Cultivar D 20 25 24 – 36 Low Yes Very Low Texas Root Rot Invasive Shot Hole Borer
Eriophyid Mite
Feather bush Lysiloma watsonii Arizona PD – E 15 15 24 Low Yes Low Texas Root Rot
Fraser photinia Photinia x fraseri Asia E 20 12 24 – 36 Low Yes Moderate
Sooty Mold
Entosporium Leaf
Spot
Mildew Aphids
Hollywood juniper Juniperus chinensis
‘Torulosa’ Northeastern Asia E 15 10 24 Low Yes Moderate
Armillaria
Root Rot
Rust
Texas Root Rot Beetle Borers
Spider Mites
Hopbush Dodonaea viscosa
Subtropical, warm
temperate Africa, North
America, Central
America, South
America, southern
Asia, Australasia
E 15 15 24 – 36 Low Yes Moderate Phytophthora
Root Rot Scales
Jerusalem thorn Parkinsonia aculeata
Western Texas,
Southern New Mexico,
Southern Arizona,
Mexico, Galapagos
Islands
D 20 25 24 – 36 Low Yes Low Texas Root Rot Invasive Shot Hole Borer
Littleleaf palo verde* Parkinsonia microphylla
Southeastern
California, Southern
Arizona, Northwest
Mexico
D 20 20 36 Low Yes Low
Borers
Caterpillars
Spider Mites
Mediterranean fan palm Chamaerops humilis Western and Central
Mediterranean E 15 15 12 Low Yes Low Texas Root Rot
Mulga Acacia aneura Australia E 20 20 24 Low Yes Low Root Rot Armillaria Invasive Shot Hole Borer
Palo blanco* Mariosousa heterophylla Mexico, Sonoran
Desert PD – E 20 15 12 - 24 Moderate Yes Low Invasive Shot Hole Borer
Purpureus smoke tree Cotinus coggygria
‘Purpureus’
Southern Europe,
Central Asia D 15 15 12 – 24 Low Yes Low
Leaf spot
Canker
Scab
Verticillium
Leaf Rollers
Pygmy date palm Phoenix roebelenii Southeastern Asia E 15 7 12 – 24 Low Yes Moderate Leaf Spot Scales
Smoke tree Cotinus coggygria Southern Europe,
Central Asia D 15 18 24 Low Yes Low Root Rot
Verticillium Armillaria
Sweet hakea Hakea drupacea Southwestern Australia E 20 20 36 Low Yes Very Low Phytophthora
Root Rot
Weeping bottlebrush Callistemon viminalis Australia E 20 20 36 Low Yes Low Armillaria
Root Rot
Western redbud* Cercis occidentalis Western United States D 20 20 24 – 36 Low Yes Moderate
Crown Rot
Phytophthora
Root Rot
Caterpillars
Scales
Table 6: Approved List of Species for Planters 2’ – 4’ in Minimum Width with Overhead Utilities (* indicates species native to the Southern California region).
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
African sumac Searsia lancea South Africa E 30 35 24 Low No Very Low Root rot
Verticillium
Australian willow Geijera parviflora Eastern Australia E 35 20 24 – 36 Low No Moderate Armillaria
Bailey acacia Acacia baileyana Southern Australia E 30 40 36 Moderate No Low Phytophthora Armillaria
Root Rot
Invasive Shot Hole Borer
Thrips
Bright n Tight cherry laurel Prunus caroliniana
‘Bright n Tight’ Cultivar E 35 25 12 – 36 Low No Moderate
Armillaria
Leaf Spot
Fire Blight
Canker
Mites
Borer
Caterpillars
Cajeput tree Melaleuca
quinquenervia
Pacific Islands,
Eastern Australia E 40 25 24 Low No Low Phytophthora
Root Rot
California fan palm*‡ Washingtonia filifera
Southwestern
California, Baja
California
E 70 20 36 Moderate No Low Armillaria Texas Root Rot Red Palm Weevil
Canary Island date palm Phoenix canariensis Canary Islands E 60 40 12 – 24 Moderate No Low Fusarium
Root rot Texas Root Rot
Carolina laurel cherry Prunus caroliniana Southeastern United
States E 30 25 36 Low No Moderate
Armillaria
Fire Blight
Root rot
Rust
Scales
Catalina cherry* Prunus ilicifolia ssp.
lyonii Channel Islands E 35 30 24 Low No Low
Root rot
Rust
Verticillium
Virus
Chilean mesquite Prosopis chilensis South America D 30 30 36 Low No Low
Scales
Borers
Mealybugs
Stem Gall Rust
Chinese photinia Photinia serrulata Southeastern Asia E 40 30 36 Low No Low
Armillaria
Powdery Mildew
Sooty Mold
Aphids
Scales
Chinese pistache Pistacia chinensis China, Philippines D 35 35 24 Low No Low Verticillium
Root Rot Armillaria
Chinese tallow Triadica sebifera Eastern China,
Taiwan D 40 30 24 – 36 Moderate No Moderate Armillaria
Chitalpa x Chitalpa tashkentensis Cultivar D 35 30 36 Low No Low Root Rot
Verticillium Aphids
Columbia planetree Platanus x hispanica
‘Columbia’ Cultivar D 80 40 36 Moderate No Moderate
Verticillium
Mildew
Anthracnose
Desert ironwood* Olneya tesota
Northwest Mexico,
Southeast California,
Western and
Southern Arizona,
Colorado Desert,
Sonoran Desert
E 30 30 12 Low No Low
Drake Chinese elm Ulmus parvifolia ‘Drake’ China, Japan, North
Korea, Vietnam PD - E 45 50 36 Moderate No Moderate
Dutch Elm Disease
Armillaria
Phytophthora
Root Rot
Aphids
Beetle Borers
Leaf Beetles
Caterpillars
Evergreen pear Pyrus kawakamii China, Taiwan PD – E 30 30 24 – 36 Low No Moderate Fire Blight
Sooty Mold Verticillium Aphids
Whitefly
Flaxleaf paperbark Melaleuca linariifolia Eastern Australia E 30 25 36 Low No Low
Chlorosis
Phytophthora
Root Rot
Ghost gum Corymbia aparrerinja New Guinea,
Northern Australia E 50 35 36 Moderate No Very Low Armillaria
Root Rot
Texas Root Rot
Verticillium Beetle Borers
Guadalupe palm Brahea edulis Guadalupe Island
(Mexico) E 25 15 12 Low No Low Texas Root Rot
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Hollyleaf cherry* Prunus ilicifolia California, Northern
Baja California E 30 25 24 Low No Low
Armillaria
Root rot
Rust
Sooty Mold
Whitefly
Aphids
Caterpillars
Honey mesquite* Prosopis glandulosa Southwestern United
States D 35 35 12 – 36 Low No Low
Scales
Borers
Mealybugs
Hong Kong orchid tree Bauhinia x blakeana China PD 40 25 12 – 24 Low No Moderate Leaf Spot Aphids
Chinese Rose Beetles
Jacaranda Jacaranda mimosifolia South-Central South
America PD 50 30 36 Moderate No Moderate Phytophthora
Root Rot
Oak Root
Fungus
Invasive Shot Hole Borer
Aphids
King palm Archontophoenix
cunninghamiana Australia E 70 15 24 Moderate No Moderate Phytophthora
Root Rot Texas Root Rot
Invasive Shot Hole Borer
Scale
Mealybugs
Lemon bottlebrush Callistemon citrinus Southeastern
Australia E 25 25 36 Low No Low Chlorosis Armillaria
Root Rot
Mexican blue palm Brahea armata Baja California E 50 25 12 – 24 Low No Low Crown Rot Texas Root Rot Red Palm Weevil
Mexican fan palm‡ Washingtonia robusta
Western Sonora
(Mexico), Baja
California Sur
E 100 10 36 Moderate No Low Texas Root Rot Beetle Borers
Red Palm Weevil
Mimosa Albizia julibrissin Southwestern and
Eastern Asia PD 35 20 36 Moderate No Moderate
Armillaria
Fusarium
Root Rot
Invasive Shot Hole Borer
Caterpillars
Olive Olea europaea Mediterranean E 30 30 12 – 24 Moderate No Low
Anthracnose
Armillaria
Phytophthora
Root Rot
Texas Root Rot Scales
Psyllid
Pink Dawn chitalpa x Chitalpa tashkentensis
‘Pink Dawn’ Cultivar D 35 25 36 Low No Low Root Rot
Verticillium Aphids
Pink melaleuca Melaleuca nesophila Western Australia E 30 30 36 Low No Low Phytophthora
Root Rot
Purple hopbush Dodonaea viscosa
‘Purpurea’
Subtropical, warm
temperate Africa,
North America,
Central America,
South America,
southern Asia,
Australasia
E 30 20 24 Low No Moderate Phytophthora
Root Rot Scales
Purple leaf eastern redbud Cercis canadensis
‘Forest Pansy’ Eastern United States D 30 25 24 Low No Moderate
Anthracnose
Crown Rot
Armillaria
Phytophthora
Caterpillars
Purple orchid tree Bauhinia variegata Asia PD 35 35 12 – 24 Low No Moderate Aphids
Queen palm Syagrus romanzoffiana Southern Brazil,
Northern Argentina E 50 30 24 – 36 Moderate No Moderate
Butt Rot
Armillaria
Root Rot
Texas Root Rot Scales
Spider Mites
Red flowering gum Corymbia ficifolia Western Australia E 45 60 24 Moderate No Low
Armillaria
Phytophthora
Root Rot
Texas Root Rot
Verticillium
Invasive Shot Hole Borer
Beetle Borers
Thrips
Red push pistache Pistacia x ‘Red Push’ Cultivar D 40 40 12 – 24 Low No Moderate Verticillium
Round-leafed moort Eucalyptus platypus Southern Australia E 35 35 36 Low No Very Low
Armillaria
Phytophthora
Root Rot
Texas Root Rot
Verticillium Beetle Borers
Senegal date palm Phoenix reclinata Tropical Africa E 35 20 12 – 36 Low No Moderate Leaf Spot Scales
Soapbark tree Quillaja saponaria Chile E 45 25 12 Low No Low
Strawberry tree Arbutus unedo Western Europe E 35 35 12 – 24 Low No Moderate
Anthracnose
Phytophthora
Root Rot
Rust
Scales
Thrips
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility
Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Swan Hill olive (fruitless) Olea europaea ‘Swan
Hill’ Mediterranean E 30 30 24 Moderate No Low
Anthracnose
Armillaria
Phytophthora
Root Rot
Texas Root Rot Scales
Psyllid
Velvet mesquite Prosopis velutina Arizona, Texas,
Mexico D 30 30 24 Low No Low
Scales
Borers
Mealybugs
Table 7: Approved List of Species for Planters 4’ – 7’ in Minimum Width with No Overhead Utilities (* indicates species native to the Southern California region, ‡ indicates species that should only be
considered for replacement of like species and not be installed in new planting spaces).
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility Lines
Water
Requirements Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Blue palo verde Parkinsonia florida
Western Texas,
Southern New
Mexico, Southern
Arizona, Mexico,
Galapagos Islands
D 25 20 36 Low Yes Low Invasive Shot Hole Borer
Bronze loquat Eriobotrya deflexa Southeastern Asia E 25 25 36 Low Yes Moderate
Fire Blight
Entosporium Leaf
Spot
Majestic Beauty Indian
hawthorn
x Rhaphiobotrya
splendens ‘Montic’ Cultivar E 25 10 24 Low Yes Moderate
Fire Blight
Root Rot
Verticillium
Entosporium Leaf
Spot
Aphids
Mexican bird of paradise Erythrostemon
mexicanus Northern Mexico E 25 20 24 Low Yes Low Armillaria
Root Rot
Pindo palm Butia odorata Brazil E 25 12 12 – 24 Low Yes Low Root Rot Scales
Purple-leaf acacia Acacia baileyana
‘Purpurea’ Eastern Australia E 30 30 36 Moderate Yes Very Low Phytophthora Armillaria Invasive Shot Hole Borer
Thrips
Shoestring acacia Acacia stenophylla Australia E 30 20 36 Low Yes Very Low Armillaria
Root Rot Invasive Shot Hole Borer
Sweet acacia Vachellia farnesiana Mexico, Central
America D - PD 25 25 24 – 36 Low Yes Very Low Root Rot Texas Root Rot Invasive Shot Hole Borer
Caterpillars
Willow acacia Acacia salicina Australia E 40 15 36 Low Yes Low Root Rot Armillaria Invasive Shot Hole Borer
Yellow bells Tecoma stans North America,
Central America E 25 20 36 Low Yes Moderate
Table 8: Approved List of Species for Planters 4’ – 7’ in Minimum Width with Overhead Utilities (* indicates species native to the Southern California region).
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility Lines
Water
Requirements Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Argyle apple Eucalyptus cinerea Southeastern
Australia E 50 40 36 Moderate No Moderate Armillaria
Root Rot
Texas Root Rot
Verticillium Beetle Borers
Bottle tree Brachychiton populneus Eastern Australia E 50 30 24 Moderate No Moderate Root Rot Armillaria Invasive Shot Hole Borer
Camphor tree Cinnamomum camphora China and Japan E 65 60 24 High No Moderate
Anthracnose
Armillaria
Phytophthora
Root Rot
Chilean wine palm Jubaea chilensis Chile E 80 25 12 Moderate No Low Texas Root Rot
Chinaberry Melia azedarach Asia D 50 25 36 Moderate No Low Scales
Chisos oak Quercus canbyi Texas, Mexico PD – E 50 50 24 Low No Low
Armillaria
Anthracnose
Root Rot
Scales
Spider Mites
Date palm Phoenix dactylifera
Egypt, Iraq, Kuwait,
eastern Syria,
Southeastern Turkey
E 100 40 12 – 36 Moderate No Low Texas Root Rot
Floss silk tree Ceiba speciosa Central South
America PD 60 50 12 – 24 Moderate No Low
Glossy privet Ligustrum lucidum Southern China E 50 30 36 Moderate No Moderate
Armillaria
Phytophthora
Root Rot
Sooty Mold
Aphids
Leaf Miner
Indian rosewood Dalbergia sissoo India, Southern Iran D – PD 60 40 24 - 36 Moderate No Very Low
Root Rot
Butt Rot
Fusarium
Rust
Powdery Mildew
Termites
Defoliators
Sissoo Leaf Webber
Island oak Quercus tomentella Channel Islands E 50 40 24 Moderate No Low Armillaria Verticillium
Modesto ash Fraxinus velutina
‘Modesto’
Southwestern United
States, Mexico D 50 40 36 High No Moderate
Anthracnose
Mistletoe
Root rot
Armillaria
Powdery
Mildew
Rust
Beetle Borers
Psyllid
Spider Mites
Whitefly
Montezuma cypress Taxodium mucronatum Mexico, Guatemala PD – E 80 40 36 Moderate No Moderate Beetle Borers
Leaf Beetles
Netleaf oak Quercus rugosa
Mexico, Guatemala,
Arizona, New Mexico,
Western Texas
E 60 40 36 Moderate No Moderate Root Rot
Powdery
Mildew
Sooty Mold
Sudden Oak
Death
Verticillium
Scales
Spider Mites
Spittlebugs
Aphids
Mistletoe
Peepul tree Ficus religiosa India, Southeast Asia E 100 100 24 Moderate No Moderate Armillaria
Root rot Scales
Queensland bottle tree Brachychiton rupestris Northeast Australia PD 35 30 24 – 36 Moderate No Moderate Root Rot
Roberts’ Western sycamore Platanus racemosa
‘Roberts’ Cultivar D 50 50 36 Moderate No Moderate
Armillaria
Phytophthora
Mistletoe
Anthracnose
Invasive Shot Hole Borer
Leaf Miner
Scales
Spider Mites
Shamel ash Fraxinus uhdei Central Mexico,
Central America PD – E 80 60 36 High No Moderate
Fusarium
Root rot
Sooty Mold
Verticillium
Armillaria
Aphids
Scales
Whitefly
Silk oak Grevillea robusta Southeastern
Australia E 65 60 36 Moderate No Low Phytophthora
Root Rot Scales
Sky Climber live oak Quercus virginiana ‘Sky
Climber’
Southern United
States PD – E 80 100 24 – 36 Moderate No Moderate
Armillaria
Phytophthora
Root Rot
Verticillium Insect Galls
Thornless honey locust Gleditsia triacanthos var.
inermis
Central and Eastern
United States D 60 40 36 Moderate No Moderate
Mistletoe
Phytophthora
Root rot
Verticillium
Invasive Shot Hole Borer
Caterpillars
Insect Galls
Pod Gall Midge
Common Name Botanical Name Species Origin Foliage
Type
Maximum
Average
Height
(feet)
Maximum
Average
Width
(feet)
Average
Annual
Growth
Rate
(inches /
year)
Potential for
Roots to
Cause
Infrastructure
Damage
Compatible
with
Overhead
Utility Lines
Water
Requirements
Disease Notes Pest Notes
Susceptible Resistant Susceptible Resistant
Tipu tree Tipuana tipu Bolivia, Southern
Brazil D – PD 50 50 24 – 36 High No Moderate
Velvet ash* Fraxinus velutina Southwestern United
States, Mexico D 50 40 24 High No Moderate
Anthracnose
Mistletoe
Root Rot
Rust
Beetle Borers
Spider Mites
Whitefly
Table 9: Approved List of Species for Planters > 7’ in Minimum Width with No Overhead Utilities (* indicates species native to the Southern California region).
TREE PLANTING
Soil Testing
Prior to species selection for any planting site, soil samples should be taken to determine soil
pH, nutrient availability and presence of heavy metals or other materials that may be harmful or
reduce growth of new trees on the site. The samples should be submitted to a City approved
laboratory facility for analysis. Samples should be taken according to the methodology
described in the ISA Best Management Practices – Soil Management for Urban Trees
summarized below.
• Ten (10) core samples should be taken from the upper six to eight inches (6” – 8”) of site
soil using a soil probe or augur for every one thousand square foot (1,000 sq. ft.) area to
be tested.
• If the site is less than one thousand square feet, a minimum of ten core samples should
be taken.
• Scrape aside any layer of mulch, litter, or turf before taking the sample.
• Core samples should be representative of the diversity of the site.
• Combine the ten core samples into a single sample bag to be submitted to the laboratory
for analysis.
• Remove any rocks and/or debris from the sample before submittal.
Species selection
Refer to the approved species list for selection of the species that is appropriate for the size of
the available planting space and presence or absence of utility lines (Tables 4 – 9). To the extent
possible, species should be chosen that maximize, without exceeding, the use of the available
space. For example, if the available planter space has a minimum width of six feet (6’), the
species should be chosen from the list of trees for a four-to-seven-foot (4’ – 7’) planter. Trees
from the two to four-foot (2’ – 4’) planter size list tend to be smaller and are not likely to provide
the maximum benefits from the available planting space. Trees from the list of species
appropriate for planter sizes greater than seven feet (> 7’) will eventually grow too big for the
available space and are likely to have health issues and infrastructure conflicts.
Adjacent infrastructure should be considered when developing the list of potential species to
plant at a site. The Approved Species List in Table 4 list the potential for roots to damage
infrastructure. Species with moderate to high potential for hardscape damage may not be
appropriate for planting adjacent to critical infrastructure.
Nursery Stock Selection
Obtaining healthy, well-structured nursery stock is essential for the establishment of healthy,
well-structured trees. Nursery stock should be free of pests and diseases with a visible root flare
to be accepted for installation in the City of Palm Springs. Codominant leaders, or trees with
large pruning wounds from the recent removal of a codominant stem should also be rejected.
Pruning of young trees in the nursery is a common industry practice, however, the pruning cuts
should be made according to ANSI A300 Tree Care Standards and ISA BMPs. Trees with flush
cut pruning wounds and/or stubs left after pruning should not be accepted.
Ideally the trees should be inspected at the nursery prior to delivery, but if this is not feasible,
the inspection should occur prior to offloading from the delivery truck. To the extent possible the
roots at the container edge should be inspected to make sure they have not been turned back
by the container and begun to form J-roots. J-roots will continue to grow inward forming a balled
root system instead of growing out into the surrounding site soil. As the young tree grows and
requires more water uptake from the roots, the small root area will not be able to accommodate
the demand. The young tree can experience drought stress symptoms regardless of the amount
of water provided and eventually die. Figure 6 illustrates some of the conditions that would
indicate healthy nursery stock compared to conditions that would lead to rejecting delivery of a
nursery tree.
Figure 6: Conditions for Selecting Nursery Stock
Tree Installation
Prior to excavation of any tree planting site the location of underground utilities should be
verified either internally by the City staff or with a contracted underground utilities locating
service such as DigAlert. Once the site has been verified safe for excavation, the new tree will
be installed according to the following specifications and as illustrated in Figure 7 (Further detail
can be found in Appendix B, ISA Best Management Practices Tree Planting and ANSI A300
Tree Care Standards Clause 10 – Planting and Transplanting):
• Excavate the planting hole twice the width of the container and to a depth one to one
and half inches (1” – 1 1/2 “) less than the depth of the container soil,
o The depth can be adjusted if needed by replacing excavated soil, water the fill
and compacting it by foot,
• Remove excess soil around the base of the tree while it is still in the container to expose
the root flare if necessary,
• Place the tree in the planting hole while still in the container to check that the container
soil level is one to one- and one-half inches (1” – 1 ½”) above the site grade,
o The depth can be adjusted if needed by replacing excavated soil, water the fill
and compacting it by foot,
• Once the depth of the planting hole has been properly adjusted
o For plastic containers (15-gallon, 20-gallon, etc.):
Carefully remove the root ball from the container by squeezing or banging
on the sides to free the soil from the container and sliding the container
from the root ball. Do not pull the tree out of the container by the
trunk or turn the container upside down.
Gently disturb the outer parts of the root ball by hand to free any roots
that may have been constricted by the container. This will encourage
outward expansion of the roots into the surrounding soil.
Place the root ball in the center of the hole supporting it with shovels or
boards to keep it intact and in the proper position.
Begin backfilling with native soil.
• Remove any debris, turf, mulch, or litter from the native soil prior
to backfilling.
• If soil amendments are recommended based on the pre-
installation soil sample analysis, they should be thoroughly mixed
with the native soil prior to being placed in the planting hole.
o Amended soil should only be used for the top eight to
twelve inches (8” – 12”) of backfill unless otherwise
specified.
• Backfill soil in six-to-eight-inch (6” – 8”) layers.
o Water in and compact each layer by foot.
• Once the backfill has reached 2/3 the height of the root ball, the
supports can be removed.
o Backfill the gap left by supports, water and compact by
foot.
o Continue adding layers of soil, watering and compacting
until the backfill is level with the surrounding grade (the top
of the container soil should be one to one- and one-half
inches [1” – 1 1/2”] above grade).
• Blend the edges of the container soil with the surrounding grade to
create a gentle slope from the top of the container soil to the
surrounding grade.
• Cover any exposed roots on the edges. Do not cut exposed
roots unless recommended by a Certified Arborist.
• Remove any backfill soil that is covering the original container soil.
The nursery soil will likely be significantly different in composition
and drainage from the native soil. If the nursery soil is covered by
native backfill, a soil barrier may result, which can prevent water
from penetrating into the root ball. As the tree begins to establish
at the site, the roots will expand into the surrounding soil and this
will be less of an issue, but for the first few months, most of the
absorbing roots will be within the original container soil.
Build a berm from remaining backfill soil to create a watering basin
around the new tree.
• Berm should be four to six inches (4” – 6”) outside the edge of the
original container and two to three inches (2” – 3”) high.
• Compact the berm by hand.
Fill the basin with water and allow water to infiltrate the soil completely.
Once water has completely drained from the basin, fill with water a
second time.
o For boxed trees
Follow the installation process above with these exceptions:
• For twenty-four (24”) and thirty-six-inch (36”) boxes remove the
bottom boards from the box before placing the tree in the planting
hole
• For forty-eight-inch (48”) boxes and larger, remove every other
bottom board prior to placement in the planting hole.
• Do not cut the straps or remove the box sides until the backfill has
reached 2/3 the height of the box, doing so can lead to collapse of
the unsupported root ball, damaging the roots.
• Backfill the gap created by the removal of the box sides in six-to-
eight-inch (6” – 8”) layers, water each layer and compact the soil
with shovels and by foot before applying the next layer.
New Tree Support and Trunk Protection
Double staking with wooden stakes is usually adequate for most newly installed container trees
up to forty-eight-inch (48”) box size. Trees from larger containers or balled and burlapped trees
with small root balls relative to tree height may be too tall to be supported by wooden stakes.
For these trees, guying and/or root ball anchoring may be the preferred support method. Details
and methodology for guying and root ball anchoring can be found in the ISA Best Management
Practices Tree Support Systems – Cabling, Bracing, Guying, and Propping and the ANSI A300
Tree Care Standards Clause 7 – Supplemental Support Systems.
TREE STAKE INSTALLATION
Figure 7 illustrates the correct placement and attachment of the double stake support system.
The process is as follows:
• Remove the nursery stake from the tree and the associated ties. If the stake cannot be
completely removed without damaging the tree or roots, cut the stake flush with the
ground. If the entire stake is removed, backfill the hole and compact by hand or with a
small trowel. Avoid damaging the roots or trunk while backfilling he stake hole.
• Place the two untreated lodge pole pine or Douglas fir stakes on opposite sides of the
tree perpendicular to the direction of the prevailing wind for the planting site.
• Drive stakes into native undisturbed soil, outside the planting hole to a minimum depth of
two inches (2”). The stakes need to be driven into the ground straight and not at an
angle.
• Attach the tree to the stake using 36” EZ-Band Self Locking Tree Ties or an equivalent
approved by the City.
o Place first pair of ties at the highest point on the trunk where the tree stands
upright. The tie should not contact, cross, constrict or interfere with any branch in
the canopy.
o Each tie will be looped in a figure-8 orientation from the trunk to the stake (Figure
7).
o The opposite tie in the pair should be placed so that it contacts the trunk just
above or below the point of the first tie without overlapping.
o The dull side of the tie should be placed flat against the trunk on this side of the
loop.
o If the distance from the trunk to the stake is greater than can be reached by a
single tie, multiple ties can be linked by passing the end of one through the self-
locking loop of the second tie. A knot is tied on the end of the first tie to prevent it
from slipping through the self-locking loop. The connection and knot should be
placed as far from the trunk as possible.
o Place the end of tie through the self-locking loop against the stake and pull it
through until the desired tightness is reached.
Ties should allow the trunk to move up to three times (3x) the diameter in
all directions. Ties that are too loose will not support the tree properly, ties
that are applied too tight will not allow the tree to develop supporting roots
and reaction wood that will be necessary once the stake is removed. Over
tightened stake ties can also lead to the trunk snapping above the tie
point in heavy winds and are more likely to become embedded in the
trunk sooner as the tree grows.
o Secure the ties to the stake with a small nail driven through the self-locking loop
to hold them in place and prevent the end from sliding back through the loop. The
remaining end of the tie can be cut off after the tie is secured.
o A second pair of ties should be installed in the same manner at approximately
half the distance from the first set of ties and ground level.
o The top of the stakes should be cut off approximately one inch (1”) above the
attachment point of the top ties and at least six inches (6”) below the lower
branches of the canopy.
Figure 7: New Tree Installation Specification
TREE STAKE INSPECTION
Stakes and ties should be inspected at least once every six (6) months after installation until
they are removed. Broken or loose stake and/or ties need to be replaced. The contact point of
the tie and the trunk should also be inspected for indications that the tie is constricting the
growth of the trunk. The tie should be loosened or replaced if it is constricting trunk growth or
becoming embedded in the bark.
TREE STAKE REMOVAL
Tree stakes should be left in place for a minimum of twelve (12) months and a maximum of
eighteen (18) months after installation. If after the eighteen-month period the tree has not
established sufficient support roots to prevent movement of the root plate when the trunk is
moved, or cannot stand upright once the stakes are removed, a Certified Arborist should inspect
the tree and roots to determine the course of action for the tree.
MONITORING OF NEWLY PLANTED TREES
For hand watered trees, the scheduled visits are an opportunity to evaluate tree health and site
conditions. Trees that show signs of pests, disease, stress, or other declining health should be
noted on the site in the City’s Electronic Inventory Software System for follow up action.
Prior to installation of new trees on planting sites that will be watered by an automatic irrigation
system, a schedule of monitoring visits should be developed with the responsible party
assignment. These visits should occur weekly for the first three months after installation and
then bi-weekly through the first year. After year one, the frequency of visits can remain biweekly
or transition to monthly as needed.
APPENDIX A – SOURCES
American National Standards Institute. 2023. A300 Tree Care Standards. Tree Care Industry
Association, Londonberry, NH. American National Standards Institute. 2023. A300 Tree
Care Standards. Tree Care Industry Association, Londonberry, NH.
Costello, Laurence R., Gary Watson, E. Thomas Smiley, and Richard Hauer. 2023. Best
Management Practices – Root Management. International Society of Arboriculture,
Atlanta, GA.
Lilly, Sharon J., Edward F. Gilman, and E. Thomas Smiley. 2019. Best Management Practices –
Pruning. Third Edition. International Society of Arboriculture, Atlanta, GA.
Matheny, Nelda, E. Thomas Smiley, Ryan Gilpin, and Richard Hauer. 2023. Best Management
Practices – Managing Trees During Site Development and Construction. Third Edition.
International Society of Arboriculture, Atlanta, GA.
Scharenbroch, Bryant C. and E. Thomas Smiley. 2021. Best Management Practices – Soil
Management for Urban Trees. Second Edition. International Society of Arboriculture,
Atlanta, GA.
SelecTree. UFEI. 1995-2025. Cal Poly University, San Luis Obispo. https://selectree.calpoly.edu
Smiley, E. Thomas, Sharon Lilly, Les Werner, and Beth Brantley. 2020. Best Management
Practices – Tree and Shrub Fertilization. Fourth Edition. International Society of
Arboriculture, Atlanta, GA.
Smiley, E. Thomas, Nelda Matheny, Sharon Lilly, Brian Kane, Ryan Klein, Beth Brantley.
2025. Best Management Practices – Tree Risk Assessment. Third Edition. International
Society of Arboriculture, Atlanta, GA.
UC IPM Statewide Integrated Pest Management Program. University of California Agriculture &
Natural Resources. https://ipm.ucanr.edu/index.html
Watson, Gary. 2014. Best Management Practices – Tree Planting. Second Edition. International
Society of Arboriculture, Atlanta, GA.
Wiserman, P. Eric and Michael J. Raupp. 2016. Best Management Practices – Integrated Pest
Management. Second Edition. International Society of Arboriculture, Atlanta, GA.
APPENDIX B – ANSI STANDARDS AND ISA BMP LINKS
American National Standards Institute (ANSI)
ANSI A300 Tree Care Standards
Clause 1 – 4: Scope, Purpose, Application, and General Info
Clause 5: Pruning
Clause 6: Soil Management
Clause 7: Supplemental Support Systems
Clause 9: Management During Site Development and Construction
Clause 10: Planting and Transplanting
Clause 11: Integrated Vegetation Management (IVM)
Clause 12: Root Management
Clause 13: Tree Risk Assessment
Clause 14: Integrated Pest Management
Clause 15: Industry Definitions
International Society of Arboriculture (ISA) Best Management Practices
Pruning
Soil Management for Urban Trees
Tree Support Systems
Managing Trees During Site Development & Construction
Tree Planting
Root Management
Tree Risk Assessment
Integrated Pest Management
Tree and Shrub Fertilization
APPENDIX C – ADDITIONAL TREE CARE RESOURCES
Trees Are Good, International Society of Arboriculture (ISA)
www.treesaregood.org
California Department of Forestry and Fire Protection Urban Forestry Program
https://www.fire.ca.gov/what-we-do/natural-resource-management/urban-and-community-
forestry
United States Forest Service
https://www.fs.usda.gov/learn/trees
University of California Agriculture and Natural Resources Master Gardner Program
https://mg.ucanr.edu/