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Yakima Tree Board
BIMONTHLY MEETING
City Council Chambers
Monday, April 28, 2025
5:00 p.m. - 6:00 p.m.
YTB Members:
Jheri Ketcham, Daniel Layton, Scot Stephens, Ken Tolonen
City Planning Staff: Eric Crowell (Senior Planner)
City Council Liaison: vacant
Agenda
I. Approval of the Meeting Minutes from September 18, 2023
II. Public Comment
III. Urban Forestry Management Plan
IV. For the Good of the Order
V. Adjourn
Next Meeting: TBD in City Council Chambers
It shall be the responsibility of the tree board to study, investigate, develop, update, and administer a
written plan for the care, preservation, pruning, planting, replanting, removal or disposition of trees and
shrubs in parks, along streets and in other city-owned public areas. The tree board shall consider,
investigate, make findings, report and make recommendations regarding any special matter or question
coming within the scope of its work.
Yakima Tree Board
DRAFT
Minutes of September 18, 2023
Board Members Present: Lance Forsee, Jheri Ketcham, Ken Tolonen
Absent and Excused: Daniel Layton
City Staff: Eric Crowell (Senior Planner)
______________________________________________________________________________
Introduction and Welcome
The bimonthly meeting of the Yakima Tree Board convened at 5:04 p.m. in City Council Chambers.
Approval of the Meeting Minutes from May 15, 2023
Jheri made the motion to approve the previous meeting’s minutes, and Lance seconded the motion.
The motion was passed by consensus.
Public Comment
No public comments were made.
Public Works RFQ/P: Certified Consulting Arborist; Urban Forestry Management Plan
Eric discussed the announcements regarding Public Works looking for a certified consulting arborist,
along with a consultant for the urban forestry management plan.
For the Good of the Order
Nothing further was discussed.
Adjournment
The meeting was adjourned at 5:16 p.m. The next Yakima Tree Board meeting will be held on Monday,
November 20, 2023 in City Council Chambers.
CITY OFYAKIMA
MANAGEMENT PLAN MAY 2024
PRODUCED BY
ARBORPRO
MANAGEMENT PLAN
TABLE OF CONTENTS
03 EXECUTIVE SUMMARY 11 SECTION 2: BENEFITS OF A
HEALTHY URBAN FOREST
06 INTRODUCTION 14 SECTION 3: TREE
MANAGEMENT
07 SECTION 1: HIGHLIGHTS AND
RESULTS OF CURRENT DATA
21 POLICIES AND OBJECTIVES
24 SURVEY AND RESULTS
ArborPro, Inc. has crafted this comprehensive Urban Forestry
Management Plan for the City of Yakima, Washington, aimed
at addressing both current and future tree management needs.
Utilizing extensive data provided by the City, which includes
details on tree locations, species, trunk diameters, and
conditions, we have been able to assess the present state of
Yakima’s urban forest comprehensively. This plan strategically
analyzes the tree inventory data to align with the City’s urban
forestry goals looking forward.
Beyond outlining necessary maintenance and planning
strategies, this report elucidates the multifaceted benefits that
urban trees offer to Yakima. It details not only the economic
advantages but also the environmental and social gains that a
well-maintained urban forest brings to the community. This
management plan serves as a foundational document,
designed to guide the City’s efforts in nurturing and expanding
its green infrastructure, thereby enhancing the quality of life for
all its residents.
EXECUTIVE SUMMARY
03
SIGNIFICANT FINDINGS FROM THE 2024 DATASET
A robust 90% of Yakima’s tree population is
classified in “good” condition, indicating healthy and
sustainable urban forestry practices.
Most Common Species: The inventory identifies
arborvitae as the predominant species with 973 trees
(14.17%), followed by red maple with 500 trees
(7.28%), Norway maple with 462 trees (12.43%),
honey locust with 335 trees (9.02%), and silver
maple with 302 trees (4.04%).
Small Tree Categories: The most common small
trees (00-03” DBH) include columnar maple (103
trees), honey locust (50 trees), and Norway spruce
(45 trees).
Large Tree Categories: The largest trees (over 25”
DBH) are notably fewer, with Norway spruce (4
trees), crab apple (3 trees), and red maple (3 trees)
leading this category.
Species Richness: A total of 95 distinct species have
been documented within the inventory.
TREE SPECIES DIVERSITY
04
The latest tree inventory for the City of Yakima encompasses a diverse urban forest situated within public street rights-of-way (ROW).
The inventory accounts for a total of 6,867 trees, representing a vital component of the city’s green infrastructure.
TREE HEALTH AND CONDITION
ENVIRONMENTAL AND ECONOMIC
BENEFITS
Annual Environmental Contributions: Trees in
Yakima contribute approximately $10,400 in
environmental benefits annually.
Carbon Dynamics: The carbon sequestration is
valued at $10,400/year, while stored carbon holds an
estimated value of $712,000.
Water Regulation: The urban forest helps avoid
approximately 278,000 gallons of runoff annually.
Total Tree Cover: The tree canopy extends over
75.36 acres.REPLACEMENT VALUE
The estimated total replacement cost for all trees is
calculated at $23,200,000, reflecting the substantial
investment in Yakima’s urban forestry assets.
TREE MAINTENANCE NEEDS
Recommended Pruning Cycles
Established Trees: A five-year pruning cycle is recommended
to maintain structure and health.
Young Trees: A more frequent three-year training cycle is
advocated to enhance tree form, structure, and vitality.
The City of Yakima has adopted a cyclical pruning strategy
aiming for a 5–7-year interval, demonstrating a commitment to
maintaining urban tree health effectively.
Proactive Maintenance Strategies
Young Trees: Small trees benefit from a three-year pruning
cycle, which helps correct structural defects early, reducing
long-term maintenance costs and ensuring their robust
growth as they mature.
Established Trees: Regular inspections and maintenance
every five years help address specific issues like deadwood
and clearance problems, tailored to each species’ natural
form.
Tree Planting as a Maintenance Strategy
Tree planting plays a critical role in urban forest management,
crucial for expanding canopy coverage, replacing trees lost to
natural causes, and enhancing biodiversity. Strategic planting not
only compensates for losses but also fosters a resilient and
diverse urban canopy.
Long-term Planning and Maintenance
This report will further delve into strategies for long-term planning
and maintenance cycles, ensuring the sustainability and health of
Yakima’s urban forest.
Overview of Current Maintenance Data
As of the latest update, specific tree maintenance histories or
detailed needs have not been provided within the current dataset.
Once this information becomes available, it will be systematically
summarized and incorporated into this management plan.
Importance of Tree Maintenance
Despite the significant time and financial investment required, the
extensive benefits provided by trees fully justify these expenses.
Proper pruning and regular upkeep are crucial for trees to deliver
maximum environmental, social, and economic benefits
throughout their lifespan.
Benefits of Regular Maintenance
Risk Mitigation: Regular maintenance reduces the risk of
falling limbs, decreases potential storm damage, and
resolves conflicts with infrastructure, such as sidewalks and
roadways.
Aesthetic Improvement: Well-maintained trees enhance the
visual appeal of urban spaces.
Growth Promotion: Corrective pruning supports healthy
growth patterns in young trees and maintains proper form in
mature trees.
Maintenance Prioritization
High-risk trees require immediate attention to mitigate safety
risks effectively and prioritize resource allocation. Following the
resolution of high-risk issues, routine pruning and tree removals
are addressed.
05
Successfully managing an urban forest requires a proactive, organized
approach that includes setting clear goals and monitoring progress. The
process begins with a thorough analysis of the current tree population's
condition and developing tailored maintenance recommendations. Using this
data, the City of Yakima is equipped to establish tree care priorities, devise
strategic planting plans, draft cost-effective budgets based on anticipated
needs, and significantly reduce the reliance on costly, reactive measures in
emergency situations.
In the spring of 2024, the City contracted ArborPro to create this
comprehensive Urban Forest Management Plan. The plan assesses the size
characteristics, condition, and species distribution of the inventoried trees,
offering a prioritized framework for the ongoing maintenance of all cataloged
trees.
Trees form a crucial segment of a community’s green infrastructure, as vital
as roads, bridges, or sewer systems. Unlike other infrastructure elements,
trees uniquely increase in value and performance over time, making them
the only infrastructural assets that improve with age.
This Urban Forestry Management Plan is designed to safeguard and
enhance this invaluable asset, akin to the way plans for stormwater, streets,
or sewers protect their respective infrastructures. It lays out detailed
strategies for how Yakima will maintain and cultivate this essential
component of its green infrastructure. The management plan is structured
into three pivotal sections:
Section 1: Highlights and Results of Inventory Data1.
This section provides an overview and detailed analysis of the tree
inventory, emphasizing key findings.
Section 2: Benefits of a Healthy Urban Forest and Community Survey
Results
2.
Discusses the extensive environmental, economic, and social
benefits of a robust urban forest and includes insights from
community feedback.
Section 3: Tree Management3.
Outlines specific management practices and priorities to ensure the
health and sustainability of the urban forest.
Home to over 97,000 residents, the City of Yakima holds the stewardship of
an extensive array of trees located in parks, public spaces, and along street
rights-of-way. Renowned for its vibrant cultural and natural resources,
Yakima boasts a longstanding commitment to its green infrastructure. This
commitment is exemplified by its designation as a Tree City USA for more
than eight years, a testament to its ongoing efforts to preserve and enhance
the urban forest.
As a critical component of the city's ecological and social fabric, Yakima's
urban forest contributes significantly to the quality of life of its citizens. This
management plan is designed to support the city's objectives in maintaining
and expanding this vital resource, ensuring that it continues to thrive and
bring benefits to the community for generations to come.
06
INTRODUCTION
SECTION 1:HIGHLIGHTS ANDRESULTS OF CURRENTDATA
07
Size Characteristics
Tree size, particularly diameter at breast height (DBH),
serves as a valuable indicator of age and value, contributing
to an understanding of the overall maturity of the urban
forest. In Yakima, while height data is not currently available,
DBH is measured at 4.5 feet above ground level. The
distribution of DBH across the urban forest provides insights
into the age distribution of the trees.
Given the variability in growth rates across different species
and environmental conditions, DBH serves as a pragmatic
proxy for estimating tree age. This metric is essential for the
city’s planning efforts, ensuring a balanced age distribution
among the tree population to maintain a healthy, sustainable
urban canopy for future generations.
SECTION 1: HIGHLIGHTS AND RESULTS OF CURRENT DATA
Figure 1, attached below, illustrates the distribution of the
City of Yakima’s trees by diameter class, offering a visual
representation of age diversity within the urban forest.
08
In spring 2024, ArborPro, Inc. received comprehensive data
from the City of Yakima, WA, detailing its urban forest. This
dataset encompasses 6,867 tree sites, focusing exclusively
on existing trees with no record of stumps, snags, or vacant
sites included.
Data Source
The tree inventory was provided in an Excel spreadsheet
format by the city, encompassing essential data fields for
each tree including address, common name, diameter, and
condition.
Assessment of Tree Inventory Data
The evaluation of tree condition within the inventory utilizes
professional judgment, rooted in extensive experience and
adherence to industry standards. This crucial data, now
integrated into this management plan, forms the basis for
both immediate and strategic urban forest management
decisions. This section summarizes key aspects of the tree
population:
Size Characteristics
Tree Condition
Species and Genus Distribution
Discussion
The distribution of tree sizes within Yakima's street tree
population is notably skewed towards smaller to semi-mature
trees. This distribution is not ideal, but it offers significant
future benefits as these trees mature, contributing to a robust,
healthy canopy. To further this growth, ArborPro
recommends a continued emphasis on planting new trees.
This will initially increase the ratio of small to large trees but is
essential for enhancing canopy cover and improving air
quality over time
Tree Condition
The condition of a tree is a qualitative measure reflecting its
health, vigor, and structure. It's important to note that
appearance alone may not accurately represent a tree's
overall condition. The data, as summarized in Table 1 and
illustrated in Figure 2, categorizes the trees as follows:
Good: 70.44% (4,837 trees)
Average: 19.72% (1,354 trees)
Fair: 1.05% (72 trees)
Poor: 7.99% (549 trees)
Dead: 0.80% (55 trees)
The majority of Yakima's trees (90%) were recorded in
'Average' condition or better at the time of the inventory,
indicating a generally healthy urban forest. However,
approximately 8% of the trees are in poor condition, with a
small fraction under 1% in critical or dead conditions.
Average – The tree has no structural problems, no
damage from diseases or pests; no mechanical damage; a
full, balanced crown; and normal twig condition and vigor
for its species. Trees in this category are 95-100% healthy.
Very Good – The tree has no structural problems, no
significant damage from diseases or pests; no mechanical
damage; a full, balanced crown; and normal twig condition
and vigor for its species. Trees in this category are 90-95%
healthy.
Table 1: Tree Condition & Percentage of Population.
Good – The tree has no major structural problems, no
significant damage from diseases or pests; no significant
mechanical damage; a full, balanced crown; and normal
twig condition and vigor for its species. Trees in this
category are 80-90% healthy.
Fair – The tree may exhibit the following characteristics:
minor structural problems and/or mechanical damage;
significant damage from non-fatal or disfiguring diseases;
minor crown imbalance or thin crown; minor structural
imbalance; or stunted growth compared to adjacent trees
of the same species. Trees in this category are 60-80%
healthy.
Poor – A tree can appear healthy but may have structural
defects. This classification also includes healthy trees that
have unbalanced structures or have been topped. Trees in
this category may also have severe mechanical damage,
decay, severe crown dieback or poor vigor/failure to thrive.
Trees in this category are 40-60% healthy.
Dead – This category refers only to trees that are
completely dead. Trees in advanced states of decline that
are still alive are generally recorded as poor or critical, not
dead.
Stump – Stumps included interfere with pedestrian traffic
or pose a tripping hazard. Stumps are not included in dead
tree count.
Discussion
The distribution of tree species and genera is critical for
determining appropriate planting strategies and managing
biodiversity, which is vital for the overall health and
longevity of the tree population. According to the 10-20-30
rule for urban biodiversity—no single species should make
up more than 10%, no genus more than 20%, and no family
more than 30% of the total tree population. Figure 3 shows
the distribution of tree species representing 2% or more of
the total.
09
Rank
Top 10
Count
%
1
Arborvitae
973
14.17%
2
Red Maple
500
7.28%
3
Norway Maple
462
6.73%
4
Honey Locust
335
4.88%
5
Silver Maple
302
4.40%
6
Incense Cedar
301
4.38%
7
Chanticleer
Pear
257
3.74%
8
Columnar
Maple
250
3.64%
9
Sycamore
242
3.52%
10
Plum
235
3.42%
Species and Genus Distribution
The city maintains a variety of species, with the ten most
common as shown in Table 2 and Figure 4. Arborvitae, being
the most prevalent at 14.17%, and both types of maples,
which together exceed 14%, suggest a need for
diversification to mitigate risks associated with disease and
pest outbreaks.
Arborvitae: 14.17% (973 trees)
Red Maple: 7.28% (500 trees)
Norway Maple: 6.73% (462 trees)
Honey Locust: 4.88% (335 trees)
Silver Maple: 4.40% (302 trees)
Table 2 and figure 4 contain the top ten species distribution
of trees recorded in Yakima by count and percentage of the
total tree population. A full species frequency report can be
found in Appendix A.
Discussion
To reduce vulnerability to species-specific issues, ArborPro
advises that the planting of Arborvitae be reduced or
discontinued as it exceeds the recommended 10%
threshold. Similarly, the excessive presence of maples
requires cautious management to prevent widespread
impact from potential health issues affecting these species.
Future Planting Recommendations: It is recommended that
Yakima focuses on diversifying its urban forest by selecting
species well-adapted to the region and promoting greater
biodiversity. This strategic approach will ensure a resilient
tree population less susceptible to diseases, pests, and
environmental changes.
10
SECTION 2:BENEFITS OF A HEALTHYURBAN FOREST
11
SECTION 2: BENEFITS OF A HEALTHY URBAN FOREST
12
Trees in urban areas offer extensive environmental, social, and economic benefits. When well-maintained, trees enhance
air quality, manage stormwater runoff, and reduce energy costs, thereby offsetting the expenses associated with their
upkeep. A robust tree maintenance program is crucial in maximizing these benefits, ensuring that the investment in tree
care yields substantial returns for the community.
Quantifying Tree Benefits
The i-Tree Eco application, a tool designed to assess urban forests and calculate their benefits in monetary terms, was
utilized to quantify the contributions of Yakima's trees. This application employs growth models and benefit calculations
specific to predominant urban tree species, providing a detailed evaluation of their environmental impact. The annual
benefit reports from i-Tree Eco highlight the significant value trees add to Yakima, encompassing improvements in air
quality, carbon sequestration, stormwater control, and overall structural value.
Key Environmental Benefits:
• Air Quality: Trees significantly improve air quality by absorbing pollutants like ozone, nitrogen dioxide, and particulate
matter while releasing oxygen. The inventoried trees in Yakima produce approximately 162.3 tons of oxygen annually.
• Carbon Dioxide Sequestration: Trees play a critical role in climate regulation by absorbing carbon dioxide during
photosynthesis and storing it in their wood, with an annual sequestration value estimated at $10,400.
• Stormwater Control: By intercepting rainfall, trees reduce the burden on public stormwater systems and infrastructure,
leading to considerable cost savings. The estimated volume of stormwater avoided annually by Yakima’s trees is 273.4
thousand gallons.
Economic Valuation
• Total Replacement Value: The total replacement cost of Yakima's urban forest, which represents the expense of
replacing each tree with another of the same size, is valued at approximately $23,184,000. This valuation underscores the
substantial capital embodied in the urban canopy.
Community Engagement and Perception
A comprehensive community survey conducted over eight weeks gathered feedback from residents on various aspects of
the urban forest. The survey, promoted via social media and the city’s website, attracted diverse opinions, highlighting the
community's high regard for tree-related benefits and their active interest in urban forest management.
Survey Insights:
A majority of respondents view the urban forest’s condition positively, with calls for continued investment in tree
planting.
Community feedback emphasized the importance of tree diversity, proper maintenance, and the expansion of
educational and participatory initiatives related to urban forestry.
Community Priorities:
Enhancing tree care education and involvement in tree-related activities.
Improving the diversity and health of the urban forest to ensure its resilience against pests, diseases, and
environmental changes.
Strategic Recommendations
Based on the i-Tree analysis and community feedback, it is recommended that Yakima:
Continues to invest in planting a diverse array of tree species to enhance ecological resilience and aesthetic value.
Expands community engagement efforts through educational programs and participatory planting events, fostering a
deeper connection between residents and their urban environment.
13
SECTION 3:TREE MANAGEMENT
14
SECTION 3: TREE MANAGEMENT
Recommended Maintenance and Tree Risk
Currently, no specific maintenance data has been provided for inclusion in this plan. Once available, a detailed description
and summary of maintenance recommendations will be appended. Meanwhile, the following framework is suggested for
categorizing and prioritizing Yakima's trees according to their maintenance needs:
• Priority 1 Prune: Address trees that pose the highest risk first. These include trees with hazardous conditions such as
deadwood, hangers, or broken branches that threaten safety. Trimming these trees is critical to remove any immediate
dangers they pose to the public and property.
• Priority 1 Removal: Trees in this category often have severe defects that are not practical or cost-effective to treat. They
typically feature a large portion of dead crown and represent a high risk of failure. Removal is recommended to mitigate
potential hazards.
• Priority 2 Prune: This category includes trees that need trimming to remove deadwood, correct structural issues, or clear
obstructions but do not pose as immediate a risk as Priority 1 trees.
• Priority 2 Removal: Trees that should be removed due to lesser risks than those in Priority 1. Attention to these trees
should follow the management of Priority 1 trees.
• Routine Prune: Regular horticultural pruning is required to correct structural problems or manage growth to avoid
interference with infrastructure.
• Training Prune: Focuses on smaller trees, typically less than 20 feet in height with a DBH of less than 8 inches. Pruning
aims to minimize future maintenance by correcting or eliminating weak or problematic branches early in the tree’s life.
• Stump Removal: Removal of stumps, particularly in high-traffic areas where they pose tripping hazards, is
recommended. This includes the removal of snags, which are essentially tall stumps.
Purpose and Strategy
The primary purpose of this Urban Forest Management Plan is to establish a comprehensive framework for both the short-
term and long-term maintenance of Yakima's urban trees. Implementing a structured pruning cycle, ranging from 5 to 7
years, is a critical component of this strategy. This section serves as a foundation for justifying funding requests and
understanding the overall maintenance needs of Yakima’s urban forest.
Understanding Tree Inventory Data
Tree inventory data provides a crucial snapshot of the current condition and maintenance requirements of Yakima's trees.
By prioritizing tree maintenance based on this data, the City can significantly reduce the risk of tree-related incidents.
However, as tree conditions can change rapidly, it is essential to combine routine maintenance with ongoing monitoring to
identify trees that may pose future risks.
15
Implementing the Plan
The initial implementation of this management plan will
prioritize trees that pose the greatest risk at the time of the
inventory. Following this, the management focus will shift to
training and routine pruning. This dynamic workflow allows
adjustments based on community needs and emerging
priorities, such as addressing storm-damaged trees more
urgently than routine maintenance tasks.
Planting New Trees
For vacant planting sites, the default action is to "Plant Tree".
This proactive approach supports the continuous growth of
the urban canopy, essential for enhancing environmental
benefits and the aesthetic value of Yakima’s urban
landscape.
Priority Maintenance
The main objective of a tree inventory is to prioritize
maintenance, allowing for systematic assignment of tree
care based on observed risks:
• Priority 1 Pruning and Removals: These are addressed
first, involving trees that pose the highest immediate risk to
public safety or property. Pruning may involve removing
hazardous limbs, while removals are reserved for trees
with defects that cannot be cost-effectively or safely
remedied.
• Priority 2 Pruning and Removals: Addressed after all
Priority 1 tasks, these involve trees that pose less
immediate risks. Pruning might include the removal of
deadwood or correction of structural issues, and removals
are for trees that still pose considerable risks but are less
urgent than Priority 1 trees.
• Routine Pruning: Scheduled after priority maintenance,
this includes trees in the Routine Prune category and
involves general maintenance to prevent future problems
and maintain tree health and aesthetics.
Proactive Maintenance
Proactive maintenance involves systematic management
over time, integrating trees into a pruning cycle that
addresses health and form. This method is cost-effective in
the long run as it reduces the likelihood of emergency
situations and allows for regular monitoring of potential
problem trees.
Routine Pruning Cycle
All trees not designated for priority pruning or removal
should be included in the routine pruning cycle. This cycle
aims to maintain trees that pose little to no immediate risk
but could benefit from regular care to prevent future issues.
ArborPro suggests a five-year cycle for routine pruning,
proposing that approximately one-fifth of the tree
population be pruned each year.
Priority and Proactive Maintenance
Recognizing the significant value of its urban trees, the City
of Yakima is committed to maintaining this asset through a
proactive maintenance schedule. This approach not only
systematically reduces risk but also enhances the overall
health of the urban trees, stabilizes maintenance budgets,
and facilitates long-term planning.
Maintenance Cycles
ArborPro recommends implementing a structured
maintenance regime:
• Routine Tree Trimming: Conducted on a five-year cycle,
this involves pruning trees that are assigned a routine prune
recommendation.
• Small Tree Training: Performed every three years, this
focuses on structural pruning of young trees to promote
healthy growth patterns.
These proactive maintenance activities are distinct from
priority maintenance, which involves addressing trees that
pose immediate risks.
16
Small Tree Training Cycle
Although the City of Yakima has an adequate number of newly planted trees, planting additional trees will help promote a
healthy urban forest for years to come. It is also important to remember that older, more mature trees provide the most
benefits to the community. The City must promote tree preservation and proactive tree care to ensure older trees survive
as long as possible. A typical Urban Forestry objective is to have an uneven-aged distribution of trees at the street,
neighborhood, and citywide levels. ArborPro recommends that Yakima support a strong planting and maintenance
program to ensure that young, healthy trees are in place to fill gaps in tree canopy and provide for gradual succession of
older trees. Tree planting and tree care will allow the distribution to normalize over time.
Trees included in the Small Tree Training Cycle are typically less than 8 inches DBH (though sometimes larger DBH trees
are included) and will benefit from structural pruning and pruning to promote form true to the species. Young trees tend to
have a higher growth rate and therefore require a shorter pruning cycle than mature trees. For this reason, ArborPro
recommends a three-year cycle for young tree training.
Establishing a training cycle for young trees is equally important for Yakima’s parks. A significant amount of money has
been spent to plant new trees in many of the parks. Investing time and money to properly prune these trees will greatly
reduce future structural problems and maintenance issues.
The three-year Young Tree Training Cycle should begin on year one of the maintenance plan. For the sake of this
management plan, it will only include existing young trees. One-third of young trees should be structurally pruned each
year. The number of trees in the training cycle will fluctuate as new trees are planted and as older plantings become
established and no longer require training. Therefore, the amount of money spent and the number of trees in the training
cycle will not remain constant. The budgetary impact of new trees is discussed in the vacant planting section.
The inventory found a total of 681 trees that would benefit from training pruning. Therefore, approximately 277 trees (one-
third of the total population) should be trained each year beginning in year one of the five-year maintenance cycle.
However, if budget does not allows, the Small Tree Training Cycle could be moved to year three for fiscal reasons.
Relatively inexpensive, small young tree training can easily be performed by trained City staff, if available. Pruning young
trees helps to reduce future maintenance costs by improving the structure and health of young trees. This type of proactive
maintenance also works towards maximizing the eco-benefits discussed earlier. ArborPro recommends that the City of
Yakima consider a modification to its 5–7-year cycle by creating an additional cycle of 3 years for young/small trees. This
young/small tree training program should be enacted as soon as possible. This program will also present a good
opportunity to interact with the community to stress the importance of trees and their regular care.
17
Importance of Tree Maintenance
Trees are naturally occurring, organic organisms. Often, they are treated as though they do not need human assistance to
thrive. While this may be true in undisturbed forests, it is certainly not true for urban trees. Urban trees require regular
maintenance to maximize the benefits they provide. When maintenance is neglected, trees can pose a serious risk to
people and property. In addition, trees in urban environments are subject to many more stressors than trees in forests or
rural areas. Urban trees grow in restricted spaces; are exposed to pollutants and road salt; are subject to soil compaction;
and can be easily damaged by mowers or other maintenance activities.
Proactive pruning and hazard mitigation greatly reduce the risk of tree failure and subsequent damage. In addition,
proactive maintenance will prolong the life of a tree and reduce future maintenance costs. A well-maintained urban forest
will be less susceptible to disease and disaster. When trees are pruned on a regular basis — or removed when they
become diseased or hazardous — it eliminates some of the pathways for potential pests and diseases. Many of these
pests and diseases attack stressed trees. Therefore, a well-maintained urban forest will be less likely to succumb to pest
infestations. In addition, species selection is an important part of maintaining a healthy urban forest. Careful species
selection will increase biodiversity and reduce the risk of a catastrophic pest infestation. Most pests have preferred hosts
(Emerald Ash Borer for example). Increasing biodiversity will limit the number of species that are susceptible to individual
pests.
While it is impossible to predict when a natural disaster will strike, a high level of disaster preparedness can be achieved
through regular maintenance. Trees that have been pruned to remove dead or hanging limbs will be less likely to
experience branch failure in high winds, thus reducing storm damage clean-up. Also, removing diseased or declining trees
from the landscape will reduce the risk of whole tree failure in major storm events. The importance of urban tree
maintenance cannot be understated. A well-maintained urban forest will provide maximum benefits to the community while
reducing the inherent risk of tree failure.
Importance of Updating Inventory Data
Trees are living organisms that change with time. Inventory data, however, is static and will not reflect the current state of
an urban forest unless it is continually updated. Whenever a tree is removed, inspected, pruned, or planted it should be
updated in the inventory. If inventory data is not properly maintained, it will quickly become obsolete and will ultimately be
of little use. Significant time and money have been invested in surveying Yakima’s trees. The only way to protect this
investment is to continually update the inventory.
Vacant Sites and Tree Planting
Currently, no specific data on potential planting locations is available for this management plan. It is recommended that the
City of Yakima undertake a thorough assessment to identify and categorize potential tree planting sites. This information
will be pivotal in developing a multiyear planting and replacement strategy to ensure the urban forest remains robust and
well-stocked.
18
Categorization of Vacant Sites
Vacant sites suitable for tree planting can be categorized based on the size
of the planting space, which determines the type of tree that can be
accommodated:
Small (4’ to 6’): Suitable for smaller tree species or under electric
utilities.
Medium (6’ to 8’): Ideal for most young trees requiring moderate space
to grow.
Large (8’ to 12’): Can accommodate larger tree species with more
extensive root systems.
Very Large (12’+): Best suited for very large species that provide
substantial canopy coverage.
Importance of a Comprehensive Planting Plan
Implementing a structured planting plan is crucial for enhancing
neighborhood landscapes and increasing the overall canopy cover across
Yakima. The plan should include annual planting targets, with a suggested
minimum of 20 to 60 trees per year to compensate for natural tree loss and
to promote biodiversity and canopy growth.
Species Diversity and Selection
Selecting a diverse array of tree species is critical to prevent the
vulnerabilities associated with monocultures, as historically demonstrated by
the devastation caused by diseases like Dutch elm disease in Syracuse,
New York. To avoid similar scenarios:
A diverse species palette should be developed, especially considering
Yakima's unique climatic challenges.
The selection should focus on species known to thrive in Yakima's
climate, with adjustments anticipated as climatic conditions evolve due to
climate change.
Continuous updates to the species list should be made based on
ongoing research and trials conducted by state foresters.
Tree Planting Considerations
Proper tree planting is crucial for the success of the urban forest:
Site Assessment: Evaluate the specific conditions of each site,
including space constraints, overhead utilities, and existing canopy.
Species Selection: Choose species that best suit the site conditions
and urban landscape goals.
Planting Techniques: Ensure trees are planted correctly to foster
healthy growth, including appropriate hole size, soil handling, and
mulching.
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Tree Maintenance Post-Planting
Effective maintenance in the years following planting is vital for the survival and establishment of trees:
Watering: Newly planted trees require consistent watering to establish roots, with specific needs varying by species
and season.
Mulching: Apply a 3 to 4-inch layer of mulch around new trees, avoiding direct contact with the trunk to prevent rot and
other issues.
Pruning: Begin structural pruning early to establish a strong form and reduce future maintenance needs.
Long-Term Care for Established Trees
Even as trees mature, they require ongoing care to ensure their health and structural integrity:
Regular Watering: Continue providing water especially during dry periods.
Ongoing Pruning: Conduct structural pruning to maintain form and prevent potential hazards.
Community Engagement
Involving the community in the tree planting process can enhance public support and awareness of the benefits provided
by the urban forest. Educational programs and community planting events can help foster a sense of stewardship among
residents.
Newly Planted Tree Maintenance
Proper young tree maintenance is just as important as proper planting techniques. If trees are not cared for after planting,
they have little chance of surviving and becoming established. Newly planted trees will require maintenance for several
years after planting.
Water
Watering newly planted trees is the most important key to their survival. Typically, it takes at least two months of watering
for a new tree to become established. The time of year and tree species will dictate how much water should be applied
after this period. The general rule is to keep soil moist to promote root growth.
Mulching
Applying mulch to newly planted trees has many benefits.Mulch will help retain soil moisture and regulate temperatures
around the root ball. Because over-mulching will have devastating effects on the long-term health of a tree, it is extremely
important to avoid piling mulch around the trunk. Spread 3 to 4 inches of mulch around newly planted trees while ensuring
the root flare is visible and mulch is not touching the trunk.
Caring for Established Young Trees
After planting, trees will take a few years to become established. The general rule: trees take one year for each inch in
caliper when planted to become established. (Caliper is the trunk diameter at 6 inches above ground.) For example, if you
are planting a 2-inch caliper tree, it will take 2 years for the roots to become fully established. Established trees still require
regular watering and will need structural pruning as they begin to grow. Structural pruning establishes a central leader;
removes dead or diseased branches; removes crossing limbs; and creates an overall structure that will benefit the tree into
maturity.
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POLICIES ANDOBJECTIVES
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POLICIES AND OBJECTIVES
Introduction
This section synthesizes key points from the management plan, providing a concise guide to effectively
implement both short-term and long-term strategies for Yakima’s urban forestry efforts.
Pruning, Removal, and Planting
Cyclical Pruning Program: Yakima has adopted a 5-7 year pruning cycle, which might be extended to 8-10
years for certain species depending on growth rates, pruning objectives, and budget considerations. This
cyclical approach helps streamline budgeting and ensures consistent tree care.
Strategic Tree Management: For trees in less-than-optimal locations, particularly large species in small
planting strips, the policy is to retain those with high vitality where feasible, maximizing benefits like carbon
storage. Trees losing vitality should be scheduled for strategic pruning or removal.
Inventory and Work Tracking: Utilizing an inventory management system will track all tree maintenance work
and associated costs, providing a crucial tool for budget planning and historical data for future staff.
Coordination and Cooperation
Information Clearinghouse: Establish a central hub of information outlining the city’s tree care goals and
procedures, including clear guidelines on when and how to contact the city arborist.
Interdepartmental Communication: Regular newsletters or memos should educate various city departments
and contractors on proper tree care to prevent unintentional damage due to lack of knowledge.
Community Education
Public Engagement: Through partnerships with local non-profits and regular educational initiatives, Yakima
aims to inform residents about the benefits of a healthy tree canopy and best practices in tree care.
Educational Outreach: The city should leverage its communication channels to distribute information on
urban forestry, focusing particularly on neighborhoods with low canopy coverage.
Planting
New Tree Planting Strategy: Addressing an annual natural mortality rate of about 2.5%, Yakima should aim to
plant at least 160 trees annually to sustain its urban forest. Partnerships with local organizations will be
essential in implementing these planting initiatives.
Planting and Training: A formal tree planting program will ensure that new trees are correctly planted and
maintained, enhancing survival rates and community involvement.
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Plan Vitality
Adaptive Management: The management plan is designed to be dynamic, adapting to new challenges or opportunities,
such as budget changes or emergent diseases.
Regular Reviews and Reports: Annual “State of the Urban Forest” reports and triennial plan reviews involving key
stakeholders will help align ongoing practices with strategic goals.
Tree City USA
Sustaining Recognition: Maintaining Tree City USA status remains a key objective for Yakima, underscoring the city’s
commitment to high standards in urban forest management.
Conclusions
Commitment to Urban Forestry: Yakima’s proactive approach and community engagement in urban forestry
management highlight its leadership in the field, as evidenced by the effective use of new tree inventories and
community surveys. The ongoing recognition as a Tree City USA reflects Yakima’s dedication to maintaining and
enhancing its urban forest.
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YAKIMA –PUBLIC ENGAGEMENTSURVEY CHARTS
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Question 13: Please tell us the most important threats to trees in Yakima (i.e. Lack of care, drought, pests,
disease, vandals, etc.)
The survey answers reflect a variety of concerns about the threats to trees in the area. Here is a summary of the key points
mentioned:
Lack of Care and Maintenance:
Multiple respondents cited lack of care as a major issue.
This includes both lack of care by property owners and city workers.
Vandalism and Damage:
Vandals and homeless individuals breaking or damaging trees.
Vandals carving into trees.
Environmental Factors:
Drought and lack of water were frequently mentioned.
Pests, disease, and climate change impacting tree health.
Heat and warming were also noted as threats.
Poor Planning and Planting Practices:
Planting trees too close to buildings, under power lines, or using unwanted varieties.
Insufficient underground space for tree growth and irrigation.
Timing of planting (e.g., planting in late November) affecting tree survival.
Community Issues:
Lack of community knowledge about the importance and care of trees.
Homeowners' lack of understanding of appropriate trees for the area.
Specific Threats:
Use of pesticides.
Damage from the unhoused.
Poor pruning practices.
Climate and Weather:
General concerns about the dry climate and its impact on trees.
Mention of drought as "normal rainfall."
Suggestions for Improvement:
Using indigenous trees and co-planting with ground cover and shrubs, specifically referencing the Miyawaki Method for
sustainable urban forests.
The responses suggest a need for better care and maintenance, improved planning, and greater community
education to address the various threats to trees in the area.
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Question 17: Is there anything else you would like to tell us?
The survey answers reflect a variety of concerns about the threats to trees in the area. Here is a summary of the key points
mentioned:
General Support for Trees:
Many respondents emphasized the need for more trees, especially real, big trees.
Some respondents thanked the city for taking care of existing trees and highlighted the importance of maintaining
large, irreplaceable trees.
Specific Suggestions:
Utilize the Miyawaki Method of planting native trees and shrubs to create urban forests.
Emphasize planting native trees, such as native maples and the Garry Oak, which are better suited for the climate and
support local wildlife.
Consider an incentive program for keeping large trees on private property.
Address the Tree of Heaven, a noxious plant, and its attraction to pests like the Spotted Lantern Fly.
Maintenance and Planning:
Trees should not only be prioritized for planting but also for maintenance.
Instead of removing old trees due to sidewalk damage, accommodate their roots to prevent future issues and reduce
the need for supplemental watering.
More significant street trees are needed to provide shade and reduce the heat island effect.
Respondents pointed out that trees offer minimal maintenance once established and enhance the beauty and livability
of the city.
City Management and Spending:
Some respondents expressed concerns about the city's lack of attention to trees and questioned how much was spent
on the survey.
There were suggestions for improving city planning, such as planting trees down the center of Yakima Ave and
investing in landscaping.
Community Involvement and Crime Prevention:
There were suggestions to involve criminals in planting and caring for trees as part of community service.
Trees are seen as a vital part of the city ecosystem, contributing to the overall quality of life.
Map and Survey Clarity:
Several respondents found the map in the survey hard to read and suggested adding street names or notable
landmarks for better orientation.
There were comments about the need for better descriptions of the survey's purpose and the area it covers.
Climate and Environment:
Yakima's arid desert climate was noted, with a call to care for existing shade and green spaces.
The need for trees to match the climate and provide benefits such as shade, beauty, and habitat for wildlife was
emphasized.
Overall, the responses show strong support for increasing and maintaining the urban forest in Yakima, with
practical suggestions for improvements in planning, maintenance, and community involvement.
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