2016 Strategic Tree Planting Plan - Highlands Garden Village, CO

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HIGHLANDS GARDEN VILLAGE June 2016

STRATEGIC TREE PLANTING PLAN

Prepared by Plan-It Geo, LLC 1|Page


STRATEGIC TREE PLANTING PLAN Highlands Garden Village Denver, CO

June 2016

Prepared for: Highland Gardens Village Prepared by: Plan-It Geo, LLC 5690 Webster St Arvada, CO 80002


Acknowledgements This project was funded by…


TABLE OF CONTENTS Introduction

1

Overview of Tree Inventory Findings: Structure

2

Tree Diversity and Composition

2

Size and Age Distribution

2

Overview of Tree Inventory Findings: Management

3

Urban Forest Condition

3

Primary Maintenance Requirements

4

Observations

4

Tree Suitability

5

Tree Longevity

6

Tree Maintenance and Replacement Costs

7

Maintenance Costs and Schedules

7

Other Maintenance Costs and Schedules

11

Watering

11

Fertilizing

11

Emerald Ash Borer Background and Treatment

13

Recommended Tree Species

15

Tree Selection Site and Tree Considerations

15 15

Resources and Funding

16

Conclusion

17

Outcomes and Recommendations

17

Appendices

I

Appendix 1. Map and table showing the unsuitable trees labeled as “Remain”

I

Appendix 2. Map and table showing the unsuitable trees labeled as “Remove and Replace”

III

Appendix 3. Estimated longevity of trees labeled as “Remain” or “Replace”

V

Appendix 4. Recommended tree species list and the associated form and suitability

VII

Appendix 5. Example of how to determine nitrogen application and amounts

XIII


FIGURES AND TABLES Figures Figure 1. Diameter size class distribution of the inventoried trees Figure 2. Condition class distribution of the inventoried trees Figure 3. Map showing the trees requiring maintenance and their associated condition Figure 4. Distribution of the estimated longevity for the unsuitable trees Figure 5. Summary of the removal and replacement schedule and costs for the trees inventoried Figure 6. Tree #1518 showing signs of nutrient deficiency and assigned a tree replacement Figure 7. Tree #1240 showing signs of nutrient deficiency Figure 8. Images to identify ash (Fraxinus) trees and the emerald ash borer Figure 9. Ash trees showing thinning of crown caused by EAB (photo not taken at HGV) Figure 10. Recommended tree species by size class Figure 11. Map showing the location of unsuitable trees labeled as “Remain” Figure 12. Map showing the location of unsuitable trees labeled as “Remove and Replace”

2 3 4 6 9 12 12 13 14 15 I III

Tables Table 1. Species composition of top ten (of 400 trees) Table 2. Diameter size class distribution Table 3. Trees by condition Table 4. Primary maintenance requirements Table 5. Summary of observations Table 6. Summary of tree suitability by species Table 7. Count of trees by estimated longevity Table 8. Average costs per activity based on DBH (diameter at breast height, 4.5’) Table 9. Annual schedule of removals and replacements and the associated costs Table 10. Estimated budget for the required maintenance tasks in a 5-year timespan Table 11. Trees noted with having a nutrient deficiency to be considered for fertilization treatment Table 12. Estimated cost for nitrogen, phosphorus, and potassium fertilizer (20-5-5) treatment for trees showing signs of nutrient deficiency Table 13. Count of ash (Fraxinus) trees by condition rating Table 14. Distribution of ash trees by diameter class and condition Table 15. Ash tree treatment cycles and costs for trees in excellent or good condition Table 16. Unsuitable trees for their planting site labeled as “Remain” Table 17. Unsuitable trees for their planting site labeled as "Remove and Replace" Table 18. Estimated longevity of trees labeled as “Remain” or “Replace” Table 19. Recommended tree species list and the associated form and suitability

2 2 3 4 4 5 6 7 8 10 12 13 14 14 15 II IV V VII


INTRODUCTION Highlands Garden Village’s urban forest is comprised of trees, shrubs, gardens, and green spaces. This “forest” is a critical component of the HGV community and contributes to environmental quality, public health, water resource management, local economies, and the beautification of often harsh, paved landscapes. Recognizing the value that trees provide and realizing the need for urban forest improvement is the first step in protecting this valuable resource. Like other valued assets, urban trees require proper planning and management to withstand the stresses caused by pests, diseases, storms, and poor practices.

HGV and the community understand the importance of trees and proper care and have supported the planting and maintenance of trees as well as an inventory and assessment. HGV understands that trees are an investment and should be properly planned using a Strategic Tree Planting Plan which addresses:

Planned urban forests are not without costs. Planting and maintaining trees requires an investment of not only monetary resources but human resources as well. It should be noted that without proper planning and maintenance, trees can have negative impacts: uprooted sidewalks, leaf collection in such areas as streets and culverts, disrupted utilities and tree damage. These effects all incur costs to the community and private landowners. However, the costs of planting new trees and maintaining existing trees are tangible and the benefits of trees are enjoyed as “public goods” by the community.

This plan assessed the inventory data to determine planting and maintenance needs, distributed over a 5-year timespan. Tree planting recommendations are based on the existing species diversity, the suitability of planting locations, and the condition and growth rates of existing species for consideration in new plantings.

“The best time to plant a tree is twenty years ago. The second best time is now”

    

Species and age diversity, condition, and maintenance needs The suitability of trees in their existing location The projected longevity of existing trees Recommended tree species for new plantings Maintenance costs and budgeting guidelines

It is recommended that new plantings occur where tree removals take place to maintain a zero net loss of tree canopy. The recommended removals in this plan are based on the condition and suitability for the existing site. This plan provides the community with the strategies for a cost effective program that strives for a healthy, sustainable urban forest.

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OVERVIEW OF TREE INVENTORY FINDINGS: STRUCTURE An analysis of the urban forest structure within HGV describes the tree population in terms of its species composition, number of trees, age classes, and tree distribution. These summaries assist tree managers in proper tree management and planting to ensure long lasting canopy and benefits are distributed equally across the community.

Tree Diversity and Composition Species composition data are essential since the types of trees present in the community greatly affect the amount of benefits produced, tree maintenance activities, and budgets. Of the 400 trees inventoried, there are a total of 40 unique tree species with the most common trees including crabapple (49), honeylocust (34), and Austrian pine (32). The top ten most prevalent species comprise 263 of the 400 trees or 66% of the population, as seen in Table 1.

Size and Age Distribution The distribution of tree ages influences the structure of the urban forest as well as the present and future costs. An uneven-age urban forest offers continued flow of benefits and a more uniform workflow allowing managers to more accurately allocate annual maintenance funds.

Table 1. Species composition of top ten (of 400 trees)

Common Name Crabapple Honeylocust Austrian pine Green ash Callery pear White ash Shubert chokecherry Serviceberry American basswood English oak TOTAL

Count 49 34 32 29 24 23 21 18 17 16 263

% of Population 12% 9% 8% 7% 6% 6% 5% 5% 4% 4% 66%

The figure below shows the diameter range (DBH or diameter measured at breast height, 4.5’) with the highest number of trees in the 6-12” range. The average DBH of the population of trees inventoried is 7”. 250

Table 2. Diameter size class distribution

Diameter Class 0-3" 3-6" 6-12" 12-18" 18-24" 24-30" TOTAL

200 150 100 50 0 0-3"

3-6"

6-12"

Count 53 105 232 5 4 1 400

% of Population 13% 26% 58% 1% 1% 0% 100%

12-18" 18-24" 24-30"

Figure 1. Diameter size class distribution of the inventoried trees

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OVERVIEW OF TREE INVENTORY FINDINGS: MANAGEMENT Tree characteristics and outside forces affect the management needs for urban trees. An analysis of the condition and maintenance requirements assists managers in planning the urban forest. Tree condition indicates how well trees are managed and how well they perform given site-specific conditions. Tree maintenance needs are inventoried for public safety reasons and for the health and longevity of the trees. Understanding the maintenance needs assists tree managers in establishing daily work plans.

Urban Forest Condition The inventory data was analyzed to identify potential trends in tree management needs and condition. Local information on the condition of street and park trees plays an important role in community planning, municipal budgeting, and use of resources. Each inventoried tree was rated for the condition of the wood and the foliage.

Table 3. Trees by condition

6%

Good - No Apparent Problems

6% 6%

Fair - Minor Problems Excellent 52% Poor - Major Problems

30%

Condition Good - No Apparent Problems Fair - Minor Problems Excellent Poor - Major Problems Dead / Dying TOTAL

Count 208 119 25 25 23 400

Dead / Dying

Figure 2. Condition class distribution of the inventoried trees

The figure above shows that over half (208) of the trees inventoried were assessed to be in Good condition. This rating is given to trees with no apparent problems such as pests/diseases, crown dieback, or trunk scars. Of the inventoried trees, 23 were rated as Dead/Dying and 25 were rated as Poor with major problems. These trees should be addressed immediately to determine maintenance needs and are included in the 5-year removal and maintenance schedule.

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Primary Maintenance Requirements The inventory required an assessment of the maintenance needs, if any, for each tree. This information along with location and the Tree Plotter application was used to guide the management and planting recommendations. The table below gives a summary of the maintenance required for the tree population. Figure 3. Map showing the trees requiring maintenance and their associated condition

Table 4. Primary maintenance requirements

Primary Maintenance Small Tree (Clean) Remove Tree Large Tree (Clean) Remove Suckers TOTAL

Count 62 30 23 1 116

% of Population 16% 8% 6% 0% 29%

Of the 400 trees inventoried, 116 require some type of maintenance. Small Tree pruning comprises the majority of the required tasks with 62 trees followed by Remove Tree and Large Tree pruning with 30 and 23 trees, respectively. Other maintenance tasks to be considered include the trees that are conflicting with the hardscape, utility lines, or other observations which are described in the following section.

Observations Table 5 shows the observations collected during the inventory. Of the 400 inventoried trees, 219 trees were noted with one or multiple observations. This accounts for 55% of the population with the majority consisting of Crown Dieback (73 trees). Cavity Decay or wounds to the trunk or limbs was observed for 47 trees (12%). Mechanical damage to the 9 trees could have been prevented or lessened by adding mulch to keep equipment away from the tree. Trees noted with Nutrient Deficiency and Pest Problems should be addressed to prevent further decline. Trees noted as being in a Poor Location are addressed in the Tree Suitability section.

Table 5. Summary of observations

Observation Crown Dieback Cavity Decay Poor Location Serious Decline Poor Structure Mechanical Damage Poor Root System Pest Problem Nutrient Deficiency TOTAL

Count 73 47 36 20 14 9 9 6 5 219

% of Population 18% 12% 9% 5% 4% 2% 2% 2% 1% 55%

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TREE SUITABILITY During the inventory, an assessment of a tree’s suitability for the location was conducted. Considerations for this included projected height, available planting space, species, obstructions, and observations. Based on these observations, 53 of the 400 trees were marked as unsuitable. 23 of these trees were classified as unsuitable but it was not recommended for removal and replacement with a different species of tree. The trees that are grouped in this category are not the optimal species for the given site but will not obstruct or damage any utilities, signs, or hardscapes. These trees will not cause any risk or public safety issues under their existing condition and are expected to reach their respective maturity in an urban landscape. Overall, the condition of these trees is either Good or Fair. This information is summarized in the table in Appendix 1. Of the 53 trees marked as unsuitable for their location, 29 trees were marked for removal and replacement with a new tree and one tree was marked for removal with no replacement. Most of the trees marked for removal and replacement are in either Poor or Dead/Dying condition. The tree marked for no replacement was determined due to the site limitations and underground utilities preventing the digging of soil and possible obstructions and issues in the future if the tree were to remain. For a full listing of the trees marked for removal and replacement which includes the recommended replacement species based on the site limitations, species diversity, soil, aspect, and potential obstructions see Appendix 2.

Table 6. Summary of tree suitability by species

Common Name Austrian Pine Callery Pear Crabapple Green Ash Honeylocust Lombardy Poplar Maple Newport Plum Plum Red Maple Serviceberry Shubert Chokecherry Siberian Elm Washington Hawthorn Littleleaf Linden Quaking Aspen Apple TOTAL

Remain 2 13 3 1 2 1 1 23

Replace 1 5 2 1 1 1 1 3 1 8 2 1 1 1 29

Remove Total 2 14 1 9 2 1 1 1 2 3 1 8 4 1 1 1 1 1 1 53

The data shows the need for proper species and site location selection when planting trees. 13% of the trees inventoried are not suitable for their location based on a variety of factors. According to Table 6 above, callery pears have the highest count of unsuitability with 14 total trees. Crabapples have the second highest count of unsuitability and the second highest count for needing removed and replaced with a total of 5 trees. Of the 53 trees marked as unsuitable, serviceberry has the highest count of needing removed and replaced, with a total of 8 trees. For a map of the location of these 53 trees, see Appendix 1 and 2.

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TREE LONGEVITY Tree longevity for those described as unsuitable for their given site was estimated based on species, DBH, condition, location, and observations. Estimates were made for longevity in ranges of less than 1 year, 1-3 years, 3-5 years, 5-10 years, 10-20 years, and 20+ years. Based on the 53 trees that are unsuitable, 18 (34%) are expected to survive 1-3 years after assessment due to their existing condition and species characteristics. The trees with the greatest estimate of longevity were assigned according to their condition and the premise that while these trees are unsuitable for the location, the site will not hinder their continued growth and survival. This information is used to help inform the maintenance strategy and schedule in the Tree Maintenance and Replacement Costs section.

6%

6%

9%

Table 7. Count of trees by estimated longevity

<1 years 1-3 years 3-5 years

25% 34%

5-10 years 10-20 years 20+ years

Longevity Estimate <1 years 1-3 years 3-5 years 5-10 years 10-20 years 20+ years TOTAL

Count % of Unsuitable Trees 5 9% 18 34% 11 21% 13 25% 3 6% 3 6% 53 100%

21% Figure 4. Distribution of the estimated longevity for the unsuitable trees

For More Information: Urban Tree Growth and Longevity Working Group “The Urban Tree Growth and Longevity (UTGL) Working Group is a unique partnership among researchers and practitioners to improve urban forestry outcomes. Our mission is to foster communication among researchers and professionals, enrich scientific exchange, and enhance the quality, productivity, and timeliness of research on tree growth and longevity through collaboration� http://www.urbantreegrowth.org/

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TREE MAINTENANCE AND REPLACEMENT COSTS The following information is based on a 5-year program budget for all relevant tree maintenance activities and is intended to provide an example of relative costs that could be incurred by the recommended activities. The budgeting recommendations are estimates based on proper urban forest management procedures and operations.

Maintenance Costs and Schedules The table to the right lists the costs based on industry estimates and is to be considered equivalent to maintenance costs performed in-house. Trees that were assessed and cited for removal place added costs on HGV. These costs depend on the size and location of the tree as well as any obstructions such as wires, buildings, hardscapes, and landscape. Due to the harsh environment of an urban landscape, it is anticipated that trees will have stresses placed on them, resulting in premature mortality. Also, as other trees do reach maturity, natural mortality is expected to occur. This is estimated to be 1% of the inventory population annually with an average removal cost of $533. Large and Small Tree Clean refers to the routine pruning that is needed for many of the trees in order to maintain public safety, aesthetic appeal, and proper form and structure of the trees. Routine pruning includes the removal of dead, dying, diseased, broken, or crossing branches. This is important in young trees in order to prevent future problems and to keep costs of mature tree pruning minimal.

Table 8. Average costs per activity based on DBH (diameter at breast height, 4.5’)

Activity

Removals (with stumps)

DBH Range 0-3in 3-6in 6-12in 12-18in 18-24in 24-30in

Cost/Tree $ 50 $ 130 $ 450 $ 500 $ 550 $ 800

>30in

$

1,250

Natural Mortality Removals (1%)

-

Tree Planting

6-12in 12-18in 18-24in 24-30in

$ $

533 500

$ $ $ $

150 200 250 350

>30in 0-3in

$ $

500 20

3-10in

$

30

Large Tree (Clean)

Small Tree (Clean)

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Based on the inventory and assessment, 29 trees are to be removed and replaced and one tree is to be removed with no replacement. These trees are prioritized and budgeted for removal in a 5-year timespan (Table 9) because of the associated risk and unaesthetic characteristics of dead and dying trees. The 30 tree removals are distributed across a 5-year timespan and across diameter ranges to create a more even and affordable tree removal budget schedule. Larger trees and those listed as experiencing Serious Decline are prioritized for removal in the first 1-3 years. Table 9. Annual schedule of removals and replacements and the associated costs Primary ID 1366 1429 1256 1564 1280 1324 TOTAL

Address 4741 West 36th Avenue 4597 West 36th Place 4 West 37th Avenue 4529-4535 West 36th Place 4410 West 37th Avenue 4415 West 36th Avenue

Common Name Maple Callery Pear Serviceberry Red Maple Lombardy Poplar Quaking Aspen

DBH 1 1 3 5 12 8

Year One Observations Serious Decline Serious Decline Serious Decline, Crown Dieback Serious Decline, Crown Dieback Nutrient Deficiency, Serious Decline, Crown Dieback Serious Decline

Replacement Species Bur Oak Serviceberry Arborvitae Bigtooth Maple Tatarian Maple 'Hot Wings' Tatarian Maple 'Hot Wings'

Removal Cost $50 $50 $50 $130 $450 $450 $1,180

Planting Cost $500 $500 $500 $500 $500 $500 $3,000

Total Site Cost $550 $550 $550 $630 $950 $950 $4,180

Primary ID 1261 1255 1257 1517 1202 1506 TOTAL

Address 7 West 37th Avenue 4527 West 37th Avenue 4 West 37th Avenue 4563 West 36th Place 4509 West 37th Place 4571 West 36th Avenue

Common Name Serviceberry Serviceberry Serviceberry Crabapple Honeylocust Newport Plum

DBH 3 3 3 5 7 10

Year Two Observations Serious Decline, Crown Dieback Serious Decline, Crown Dieback Serious Decline, Crown Dieback Serious Decline, Crown Dieback Cavity Decay Cavity Decay, Crown Dieback, Poor Structure

Replacement Species Arborvitae Arborvitae Arborvitae Crabapple Honeylocust Thornless Cockspur Hawthorn

Removal Cost $50 $50 $50 $130 $450 $450 $1,180

Planting Cost $500 $500 $500 $500 $500 $500 $3,000

Total Cost $550 $550 $550 $630 $950 $950 $4,180

Primary ID 1254 1259 1260 1518 1349 1391 TOTAL

Address 4527 West 37th Avenue 5 West 37th Avenue 7 West 37th Avenue 4555 West 36th Place 4690 West 37th Avenue 4741 West 36th Avenue

Common Name Serviceberry Serviceberry Serviceberry Shubert Chokecherry Plum Plum

DBH 3 3 3 5 7 8

Year Three Observations Serious Decline, Crown Dieback Serious Decline, Crown Dieback Serious Decline, Crown Dieback Cavity Decay, Nutrient Deficiency, Serious Decline, Crown Dieback Serious Decline Poor Location

Replacement Species Arborvitae Arborvitae Arborvitae Shubert Chokecherry Northern Red Oak Thornless Cockspur Hawthorn

Removal Cost $50 $50 $50 $130 $450 $450 $1,180

Planting Cost $500 $500 $500 $500 $500 $500 $3,000

Total Cost $550 $550 $550 $630 $950 $950 $4,180

Primary ID 1258 1434 1602 1592 1387 1388 TOTAL

Address 5 West 37th Avenue 4595 West 36th Place 4528 West 37th Avenue 4575 West 36th Place 4799 West 36th Avenue 4799 West 36th Avenue

Common Name Serviceberry Shubert Chokecherry Crabapple Crabapple Green Ash Green Ash

DBH 3 3 3 5 8 8

Observations Serious Decline, Crown Dieback Poor Structure Serious Decline Crown Dieback, Obstructing Utilities Poor Location Poor Location

Replacement Species Arborvitae Thornless Cockspur Hawthorn Serviceberry No Replacement Honeylocust Swamp White Oak

Removal Cost $50 $50 $50 $130 $450 $450 $1,180

Planting Cost $500 $500 $500 $500 $500 $500 $3,000

Total Cost $550 $550 $550 $630 $950 $950 $4,180

Common Name Apple Littleleaf Linden Crabapple Crabapple Crabapple Plum

DBH 1 3 4 5 5 7

Observations

Replacement Species Apple Swamp White Oak Thornless Cockspur Hawthorn Columnar English Oak Thornless Cockspur Hawthorn Ginkgo

Removal Cost $50 $50 $130 $130 $130 $450 $940 $5,660

Planting Cost $500 $500 $500 $500 $500 $500 $3,000 $15,000

Total Cost $550 $550 $630 $630 $630 $950 $3,940 $20,660

Year Four

Year Five Primary ID Address 1430 4597 West 36th Place 1210 4516 West 37th Avenue 1273 3717 Tennyson Street 1311 3670 Utica Street 1276 4405 West 37th Avenue 1350 4690 West 37th Avenue TOTAL 5-Year Program Total

Cavity Decay, Serious Decline, Crown Dieback Poor Location Crown Dieback, Pest Problem Cavity Decay, Poor Location Serious Decline

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Trees flagged for removal range from 0-12� with a total of 6 trees to be removed per year for an annual cost of approximately $1,180 and a total removal cost of $5,660. After year 5, all remaining trees should be scheduled for routine maintenance on a 5-year year rotation, completing maintenance in designated quadrants while addressing any new potential tree risks that arise. It is recommended that as trees are removed, new trees are planted in their place to maintain a zero net loss of tree numbers. Based on this protocol, a total of 30 trees are to be planted over the course of 5 years. The replanting of trees will follow the same schedule as removals and should adhere to the recommended tree replacements species as listed in Table 9, above. It is often recommended to perform needed maintenance such as removals and replanting in close proximity to one another to save costs. But, given the small area of HGV, replanting and removals can be dispersed across HGV which will help to increase the age diversity of the urban forest; a need that is highlighted in Table 2 within the Overview of Tree Inventory Findings: Structure section. Figure 5. Summary of the removal and replacement schedule and costs for the trees inventoried

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Table 10 provides additional information on estimated tree maintenance costs which include the removal of trees and stumps, replanting, and routine tree pruning for a 5-year period. These estimates assist HGV in preparing an annual budget and distributing an even workflow. Note that the overall cost for removal and replacement of the 30 trees is the same though the schedule is slightly different than Table 9 above. In addition, it is estimated that 1% of the urban forest population will die due to natural mortality, resulting in 4 trees per year at a total cost of $10,660 over the course of 5-years. The Large Tree and Small Tree Clean activities are routine pruning tasks needed that were identified when conducting the inventory. These costs are based on industry averages and are distributed across the 5-year timespan. After completing these required routine pruning activities, routine and cyclical pruning should be scheduled for all HGV managed trees. Table 10. Estimated budget for the required maintenance tasks in a 5-year timespan

Estimated Costs for Each Activity Activity

Removals (with stumps)

Activity Total Natural Mortality Removals (1%) 1 Activity Total

Year 1

Removals

4 4

$533

Projected Removal Costs Tree Planting Activity Total

Large Tree (Clean) 2

Activity Total

$2,132 $2,132

4 4

$3,442 Planting

6-12in 12-18in 18-24in 24-30in >30in

$500

$150 $200 $250 $350 $500

Activity Total Small Tree (Clean) 3

Year 2

Year 3

Year 4

Year 5

DBH Range Cost/Tree Total # of Trees # of Trees Total Cost # of Trees Total Cost # of Trees Total Cost # of Trees Total Cost # of Trees Total Cost 0-3in $50 14 3 $150 3 $150 3 $150 3 $150 2 $100 3-6in $130 7 2 $260 2 $260 1 $130 1 $130 1 $130 6-12in $450 9 2 $900 2 $900 2 $900 2 $900 1 $450 12-18in $500 0 0 $0 0 $0 0 $0 0 $0 0 $0 18-24in $550 0 0 $0 0 $0 0 $0 0 $0 0 $0 24-30in $800 0 0 $0 0 $0 0 $0 0 $0 0 $0 >30in $1,250 0 0 $0 0 $0 0 $0 0 $0 0 $0 30 7 $1,310 7 $1,310 6 $1,180 6 $1,180 4 $680

0-3in 3-10in*

$20 $30

4 4

$3,442

$3,312

$3,312

$16,320

$3,000 $3,000

$15,000 $15,000

23

2 0 0 0 0 2

$570 $0 $250 $0 $0 $820

2 0 0 0 0 2

$570 $0 $250 $0 $0 $820

2 0 0 0 0 2

$570 $0 $250 $0 $0 $820

$2,850 $400 $1,250 $0 $0 $4,500

11 51 62

2 10 12

$44 $306 $350

2 10 12

$44 $306 $350

2 10 12

$44 $306 $350

11 10 21

$220 $306 $526

11 10 21

$220 $306 $526

$572 $1,444 $2,016

$1,346

$6,602

2

Based on a 5-year cycle for the trees marked as Large Tree (Clean) routine pruning

$7,812

$7,812

$7,482

$1,346 $7,658

6 6

$2,812

$570 $200 $250 $0 $0 $1,020

Based on average cost of removal

$3,000 $3,000

$10,660 $10,660

2 1 1 0 0 4

$1,170

6 6

$2,132 $2,132

$570 $200 $250 $0 $0 $1,020

1

$3,000 $3,000

4 4

4 1 1 0 0 6

$1,370

6 6

$2,132 $2,132

19 2 2

Projected 5-Year Budget

$3,000 $3,000

4 4

6 6

$1,370

6 6

$2,132 $2,132

$700 $910 $4,050 $0 $0 $0 $0 $5,660

30 30

Projected Pruning Costs

$3,000 $3,000

$2,132 $2,132

5-Year Total Cost

$7,158

$37,922

3

Based on a 5-year cycle for the trees marked as Small Tree (Clean). Accounts for an additional 18 trees planted from years 1-3 (18 trees from year 1-3 divided by 2 for years 4 and 5 = 9 extra trees) * Some trees are large in diameter (>6") but still considered for Small Tree (Clean)

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Other Maintenance Costs and Schedules Watering Periods of drought are common on Colorado’s Front Range. The area is naturally a semi-arid, shortgrass prairie that would have few trees without irrigation. Growing trees here is difficult in wet years let alone in drought years. Drought makes growing healthy trees in this region all the more challenging. Properly placed and maintained trees are an asset to the environment and to the community. Proper watering techniques and schedules should be planned for HGV’s urban forest. Most homeowners realize the need for watering during the growing season, however many may not realize the need to water when their trees are dormant. During this time, some root development may occur, especially for newly planted trees. Evergreen trees are more at risk from drying winter conditions and need more water to survive because they retain their needles and can lose water all winter long. Deciduous trees most at risk from drying winter conditions are shallow-rooted species such as maples, lindens, birches and any recently planted tree. Winter Watering Tips:    

Water your deciduous and evergreen trees up to two times a month between October and March For each watering, approximately 10 gallons per inch of trunk diameter is required during periods of low soil moisture Water during the day when temperatures are above 40 degrees to allow the water to soak in before freezing night temperatures The most important area to water for deciduous trees is within the dripline (from the trunk to the outer edges of the trees branches). For evergreens, water 3-5 feet beyond the dripline on all sides of the tree  Maintain mulch 4 inches deep around trees and shrubs to retain moisture and moderate temperatures Fertilizing Trees in urban and suburban environments are often under high stress conditions due to low moisture availability, soil compaction, physical damage, nearby construction, and competition from turf and nearby trees and shrubs. Fertilizer applications may reduce, but cannot eliminate, environmental stresses such as these. It is important to keep newly planted trees watered and pruned and to keep weeds away from their bases to avoid excess stress. The best indicator of whether fertilization is necessary is a soil test. Ideally, a soil sample should be taken before trees are planted. In the absence of a soil test, the next best indicator of the need for additional fertilization of established trees is shoot growth. If new shoot growth (growth occurring in the present year) is in excess of 6 inches, then fertilization is probably unnecessary. If shoot growth is between 2 and 6 inches then fertilizer may be applied and, if shoot growth is under 2 inches, then fertilizer applications are appropriate. Foliage color is another indicator of the need for fertilization. Yellow or "off-color" leaves may indicate the need for fertilization as these symptoms generally occur on trees which are not taking up enough of one or more required nutrient. Always follow the manufacturer’s required amounts and fertilize before July or after leaf fall.

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Common treatments for nutrient deficiency first begin with a soil test to determine the insufficient nutrient. The macronutrients required by trees for growth include nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). Increased nitrogen can result in improved growth while deficiencies can lead to slower growth and visible symptoms. The micronutrients needed include iron (Fe), manganese (Mn), zinc (Zn), copper (Cu), boron (B), chlorine (Cl), and molybdenum (Mo), all in small amounts. Most soils in Colorado contain adequate micronutrients to meet the needs of landscape trees. Though, the most commonly lacking in Colorado soils is iron because of high pH levels in calcareous soil changing iron into an insoluble form which cannot be absorbed by plants. This results in iron chlorosis – a yellowing of leaves between the veins. For more information on property fertilizing practices see ISA Tree Nutrition and Fertilization Guide. Table 11. Trees noted with having a nutrient deficiency to be considered for fertilization treatment Primary ID Address Common Name Condition DBH Notes 1566

4543 West 36th Place

Silver Maple

Poor - Major Problems

9

1241

7 West 37th Avenue

Northern Hackberry

Poor - Major Problems

4

1280

4410 West 37th Avenue Lombardy Poplar

Dead / Dying

12

1361

3630 Wolff Street

Freeman Maple

Excellent

4

1518

4555 West 36th Place

Shubert Chokecherry Poor - Major Problems

5

1240

5 West 37th Avenue

Northern Hackberry

5

Fair - Minor Problems

Observations Cavity Decay, Nutrient Deficiency, Poor Root System Cavity Decay, Mechanical Damage, Nutrient Deficiency Replace: Tatarian Maple Nutrient Deficiency, Serious 'Hot Wings' Decline, Crown Dieback Nutrient Deficiency Replace: Shubert Chokecherry

Cavity Decay, Nutrient Deficiency, Serious Decline, Crown Dieback Nutrient Deficiency

It was identified during the inventory that six trees may be experiencing nutrient deficiency (see Table 11) and may require fertilizer treatment. Of these trees, two were assigned a replacement (tree #1280 and 1518) because of their poor suitability to the site. These trees, such as the one seen in Figure 6, should not be treated with fertilizer and should instead be replaced following the replacement schedule in Table 9. Each of the trees in Table 11 should be reviewed to determine if their condition is too poor to justify a fertilizer treatment.

Figure 6. Tree #1518 showing signs of nutrient deficiency and assigned a tree replacement

Figure 7. Tree #1240 showing signs of nutrient deficiency

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The following table shows the estimated cost for treating the trees showing signs of nutrient deficiency. The two trees assigned with a replacement species were not included in the cost calculation. By estimating the size of the treatment area the per tree fertilization amount was calculated. Based on the $40/8lb cost of the common fertilizer, PHC for Trees, which is a 20-5-5 mixture of nitrogen, phosphorus, and potassium (respectively), the per tree fertilization cost was determined. A total of 21 pounds of PHC for Trees is needed to treat the four trees on a total of 1,413 square feet and a total cost of $105. The cost does not include staff applicator fees. Table 12. Estimated cost for nitrogen, phosphorus, and potassium fertilizer (20-5-5) treatment for the trees showing signs of nutrient deficiency

Primary ID 1566 1241 1361 1240 TOTAL

Address 4543 West 36th Place 7 West 37th Avenue 3630 Wolff Street 5 West 37th Avenue

Common Name Silver Maple Northern Hackberry Freeman Maple Northern Hackberry

DBH 9 4 4 5

Estimated Diameter of Canopy (ft) 20 8 10 8

1/2 of Canopy Diameter 10 4 5 4

Square Feet of Canopy 900 144 225 144 1,413

lbs N Needed (3lbs per 1000ft2) 2.7 0.4 0.7 0.4 4.2

lbs of 20-55 Fertilizer Needed 14 2 3 2 21

Cost $67.50 $10.80 $16.88 $10.80 $105

Fertilizer = PHC for Trees (chosen for this example because it is commonly used for tree fertilization at a cost of $40/8 lbs)

Emerald Ash Borer Background and Treatment The emerald ash borer (EAB) was confirmed for the first time in Colorado, in the City of Boulder, in 2013. Emerald ash borer attacks and kills all true native North American ash trees, including green and white (Fraxinus americana and Fraxinus pennsylvanica, respectively), of which HGV has.This pest kills stressed and healthy trees and is so aggressive that ash trees may die within two years after they become infested. The dark green adult beetles are ½ inch long and are active from late May through July, when they feed on ash trees and lay eggs on the bark. After hatching, the resulting EAB larvae tunnel into the bark to feed in the phloem and outer sapwood layers of the tree, producing galleries that girdle and ultimately kill the tree within two to four years. Figure 8. Images to identify ash (Fraxinus) trees and the emerald ash borer

Photo Source: http://csfs.colostate.edu/forest-management/emerald-ash-borer/

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The Highlands Garden Village has a total of 52 ash (13% of the total inventory population) trees, comprised of white and green ash with an average DBH of 9 inches. Of these trees, two were assigned a replacement species.

Figure 9. Ash trees showing thinning of crown caused by EAB (photo not taken at HGV)

Table 13 below shows that of the 50 trees that are to remain, 35 or 70%, are in Good condition. This information helps to inform the treatment of the ash trees if the emerald ash borer arrives. Table 13. Count of ash (Fraxinus) trees by condition rating

Condition Excellent Good - No Apparent Problems Fair - Minor Problems Poor - Major Problems TOTAL

Count 2 35 12 1 50

% of Ash Population 4% 70% 24% 2% 100%

In preparation for EAB arrival in the Highlands Garden Village, Condition treatment should be considered. High-value ash trees on site can be treated with Emamectin benzoate or better known as Treeäge. This pesticide provides excellent protection against EAB larval development for 2-3 years with a single application. Trees in either excellent or good condition are considered for Tree-äge, since they are in better health to survive the attack from EAB. Table 14 summarizes the distribution of ash trees by diameter class and condition. All ash trees in excellent or good condition (37) were selected for estimating the cost of three cycled treatments (3 year rotation) with a total of 12-13 trees to be treated annually (Table 15). The largest and healthiest trees were selected for the first rotation (Cycle A). Annual costs range from $798 to $1,178 and are based on total DBH, tree growth, increased treatment costs, and industry standards. Total cost is estimated to be $8,512. Replantings should be considered for the 13 trees that will not be treated.

Photo Source: https://news.uns.purdue.edu/images/2016/ashborer-trees.jpg Table 14. Distribution of ash trees by diameter class and condition

Excellent Good Fair Poor TOTAL

0-3" 0 0 0 0 0

3-6" 0 0 0 0 0

DBH Class 6-12" 12-18" 2 0 34 0 11 0 1 0 48 0

TOTAL 18-24" 0 1 1 0 2

>24" 0 0 0 0 0

2 35 12 1 50

Table 15. Ash tree treatment cycles and costs for trees in excellent or good condition Year Cycle No. Trees Total DBH (inch)* Unit Price ($)* Cost ($)** 2017 A 13 126 $8.00 $1,008 2018 B 12 99 $8.20 $812 2019 C 12 95 $8.40 $798 2020 A 13 127 $8.60 $1,092 2021 B 12 100 $8.80 $880 2022 C 12 96 $9.00 $864 2023 A 13 128 $9.20 $1,178 2024 B 12 101 $9.40 $949 2025 C 12 97 $9.60 $931 TOTAL 37 326 $8,512 * 1% annual increase in DBH is assumed and 2% annual increase for cost of treatment ** 1 liter of Tree-age costs $520 and treats 33 trees with a DBH of 10"

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RECOMMENDED TREE SPECIES During the tree inventory, it was observed that the planting spaces in HGV are close to fully stocked. Only three planting spaces were identified along the streets and alleys. It is this observation that guided the recommendation to replace all trees that are marked for removal due to poor condition or it is unsuitable for the location. In the previous section, 30 replacement trees are prescribed for the trees to be removed. The species were chosen to increase diversity and be best suited for the given location.

Tree Selection It is important to choose the right tree for the right location because of the investment of time, resources, and funding, and the potential for the trees to impact and influence the community for years to come. The following lists provide considerations that should be made when selecting a tree. Site Considerations      

Available space above and below ground Water availability Drainage Soil texture and pH Sunlight levels and exposure Weather and other environmental factors

Tree Considerations      

Growth rate Mature size and form Hardiness Heat and drought tolerance Pest resistance Maintenance issues

The following provides additional recommended species for new tree plantings. For a full list of species, their form, and suitability see Appendix 4: Figure 10. Recommended tree species by size class

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RESOURCES AND FUNDING The recommendations in this plan will assist HGV in improving their urban forest through proper management distributed over the course 5 years. It will guide the community in addressing potential risks, improving management practices, and creating a cyclical maintenance schedule that will allow proper budgeting for a balanced workflow and associated costs. In order to achieve these objectives, resources and funding must be identified and utilized. The following provides some examples of useful resources, funding, and program resources.

Resources

Pruning Guidelines Sample Tree Ordinance Tree Ordinance Guidelines Tree Contracting Specifications Tree Boards Trees for Green Infrastructure Valuing Tree Benefits Urban Tree Canopy Assessments Sustainable Urban Forest Guide Tree Inventory Software Tree Care Tips Colorado Tree Coalition Colorado State Forest Service EAB Management

Funding and Building Support

Funding Sources Volunteers Outreach Programs Door hangers Tree benefits tags Media reports Tree Benefits Studies Adopt-a-Tree programs Memorial Tree Programs Arbor Day Events Community Events Tree Inventory Upkeep Backyard Tree Programs Engage the Youth 16 | P a g e


CONCLUSION The urban forest of Highlands Garden Village is a young and diverse vital resource providing numerous benefits to the community. Maintaining and increasing these benefits can only come through proper planning and management. To ensure a healthy, sustainable urban forest, HGV will need to follow the guidelines provided in this Strategic Tree Planting Plan.

Outcomes  Species Diversity: 40 unique tree species consisting primarily of crabapple (49), honeylocust (34), and Austrian pine (32)  Age Diversity: 58% of the trees are in the 6-12” diameter class showing the need for additional tree plantings for an uneven urban forest structure  Condition: 52% of the trees are classified as having a Good condition with no apparent problems  Maintenance: Of the 116 trees requiring maintenance, 62 trees need young tree pruning, a practice that will reduce their costs at maturity  Observations: 73 (18%) of the inventoried trees are experiencing some degree of crown dieback  Tree Suitability: 53 trees are deemed unsuitable for their given location and 29 are recommended for removal and replacement  Tree Longevity: Of the 53 trees deemed unsuitable, 34% are expected to only survive for an additional 1-3 years  Tree Removal and Replacement Schedule: 29 trees are scheduled to be removed and replaced in a 5-year timespan  Tree Removal and Replacement Costs: It is estimated that the removal and replanting will cost an annual $4,180 with a total 5-year cost of $20,660  Routine Pruning: Schedules for the 85 small or large trees requiring pruning will be completed over the course of 5 years, followed by routine, cyclical pruning of the entire population  New Plantings: Recommended species are based on species diversity, location, and success of the existing tree population  5-year Budget: Including removals, replacements, natural mortality, and routine pruning, the 5-year cost is estimated to be $37,922

Recommendations  The Highlands Garden Village should maintain the existing tree inventory and update it as new trees are planted  An annual evaluation of the existing work plan and a budget should be conducted and adjusted accordingly  Observations such as overwatering, planting trees in restricted planting spaces, damage caused by vehicles, and lack of young tree training should be addressed  After Year 5 of the Strategic Tree Planting Plan implementation, HGV should reevaluate and update with an inclusion of new tree planting goals and routine, cyclical pruning of all trees on a 5-year rotation The trees in Highlands Garden Village are young and growing and receiving the care and attention that is needed to ensure long lasting benefits for the entire community. The ambitious efforts of the community will continue to be a model, supported by this Strategic Tree Planting Plan. 17 | P a g e


“If you want to know your past, look into your present conditions. If you want to know your future, look into your present actions�

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APPENDICES Appendix 1. Map and table showing the unsuitable trees labeled as “Remain” Figure 11. Map showing the location of unsuitable trees labeled as “Remain”

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Table 16. Unsuitable trees for their planting site labeled as "Remain"

Primary ID 1238 1508 1507 1321 1500 1368 1322 1222 1239 1243 1237 1501 1246 1247 1603 1369 1272 1370 1587 1595 1323 1245 1204

Common Name Callery Pear Callery Pear Callery Pear Callery Pear Callery Pear Siberian Elm Newport Plum Austrian Pine Callery Pear Callery Pear Callery Pear Callery Pear Callery Pear Callery Pear Crabapple Crabapple Crabapple Shubert Chokecherry Shubert Chokecherry Washington Hawthorn Callery Pear Callery Pear Austrian Pine

DBH 8 10 13 12 8 4 7 7 8 8 8 7 6 7 7 8 4 6 6 5 4 5 2

Suitability Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain

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Appendix 2. Map and table showing the unsuitable trees labeled as “Remove and Replace” Figure 12. Map showing the location of unsuitable trees labeled as “Remove and Replace” (note: 4 trees flagged for removal are not included)

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Table 17. Unsuitable trees for their planting site labeled as "Remove and Replace" Primary ID

Common Name

DBH

Suitability

Replacement Species

1592

Crabapple

5

Remove - No Replacement

N/A

1260

Serviceberry

3

Replace

Arborvitae

1256

Serviceberry

3

Replace

Arborvitae

1254

Serviceberry

3

Replace

Arborvitae

1258

Serviceberry

3

Replace

Arborvitae

1366

Maple

1

Replace

Bur Oak

1391

Plum

8

Replace

Thornless Cockspur Hawthorn

1311

Crabapple

5

Replace

Columnar English Oak

1518

Shubert Chokecherry

5

Replace

Shubert Chokecherry

1517

Crabapple

5

Replace

Crabapple

1350

Plum

7

Replace

Ginkgo

1276

Crabapple

5

Replace

Thornless Cockspur Hawthorn

1273

Crabapple

4

Replace

Thornless Cockspur Hawthorn

1434

Shubert Chokecherry

3

Replace

Thornless Cockspur Hawthorn

1202

Honeylocust

7

Replace

Honeylocust

1387

Green Ash

8

Replace

Honeylocust

1349

Plum

7

Replace

Northern Red Oak

1280

Lombardy Poplar

12

Replace

Tatarian Maple 'Hot Wings'

1602

Crabapple

3

Replace

Serviceberry

1388

Green Ash

8

Replace

Swamp White Oak

1506

Newport Plum

10

Replace

Thornless Cockspur Hawthorn

1564

Red Maple

5

Replace

Bigtooth Maple

1255

Serviceberry

3

Replace

Arborvitae

1257

Serviceberry

3

Replace

Arborvitae

1259

Serviceberry

3

Replace

Arborvitae

1261

Serviceberry

3

Replace

Arborvitae

1210

Littleleaf Linden

3

Replace

Swamp White Oak

1324

Quaking Aspen

8

Replace

Tatarian Maple 'Hot Wings'

1429

Callery Pear

1

Replace

Serviceberry

1430

Apple

1

Replace

Apple

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Appendix 3. Estimated longevity of trees labeled as “Remain” or “Replace” Primary ID 1210 1324 1429 1430 1592 1254 1255 1256 1257 1258 1259 1260 1261 1280 1311 1349 1350 1366 1391 1434 1517 1564 1602 1202 1272 1273 1276 1321

Common Name Littleleaf Linden Quaking Aspen Callery Pear Apple Crabapple Serviceberry Serviceberry Serviceberry Serviceberry Serviceberry Serviceberry Serviceberry Serviceberry Lombardy Poplar Crabapple Plum Plum Maple Plum Shubert Chokecherry Crabapple Red Maple Crabapple Honeylocust Crabapple Crabapple Crabapple Callery Pear

DBH 3 8 1 1 5 3 3 3 3 3 3 3 3 12 5 7 7 1 8 3 5 5 3 7 4 4 5 12

Notes Replace Replace Replace Replace Remove - No Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Replace Remain Replace Replace Remain

Replacement Swamp White Oak Tatarian Maple 'Hot Wings' Serviceberry Apple N/A Arborvitae Arborvitae Arborvitae Arborvitae Arborvitae Arborvitae Arborvitae Arborvitae Tatarian Maple 'Hot Wings' Columnar English Oak Northern Red Oak Ginkgo Bur Oak Thornless Cockspur Hawthorn Thornless Cockspur Hawthorn Crabapple Bigtooth Maple Serviceberry Honeylocust N/A Thornless Cockspur Hawthorn Thornless Cockspur Hawthorn N/A

Longevity Estimate <1 years <1 years <1 years <1 years <1 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 1-3 years 3-5 years 3-5 years 3-5 years 3-5 years 3-5 years V|Page


1323 1387 1388 1500 1518 1603 1237 1238 1239 1243 1245 1246 1247 1322 1368 1501 1506 1507 1587 1204 1595 1369 1222 1370 1508

Callery Pear Green Ash Green Ash Callery Pear Shubert Chokecherry Crabapple Callery Pear Callery Pear Callery Pear Callery Pear Callery Pear Callery Pear Callery Pear Newport Plum Siberian Elm Callery Pear Newport Plum Callery Pear Shubert Chokecherry Austrian Pine Washington Hawthorn Crabapple Austrian Pine Shubert Chokecherry Callery Pear

4 8 8 8 5 7 8 8 8 8 5 6 7 7 4 7 10 13 6 2 5 8 7 6 10

Remain Replace Replace Remain Replace Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Remain Replace Remain Remain Remain Remain Remain Remain Remain Remain

N/A Honeylocust Swamp White Oak N/A Shubert Chokecherry N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A N/A Thornless Cockspur Hawthorn N/A N/A N/A N/A N/A N/A N/A N/A

3-5 years 3-5 years 3-5 years 3-5 years 3-5 years 3-5 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 5-10 years 10-20 years 10-20 years 10-20 years 20+ years 20+ years 20+ years

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Appendix 4. Recommended tree species list and the associated form and suitability The following tables provide a list of the species suitable for the Highlands Garden Village. This resource comes from the City of Denver’s Parks and Recreation Department and can be found here. Table 19. Recommended tree species list and the associated form and suitability

*Cells shaded in green are trees that are suitable for planting under powerlines but should only be planted when a larger stature tree cannot be planted.

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Appendix 5. Example of how to determine nitrogen application and amounts Determine the dimensions of the area to be fertilized. To do this, estimate the diameter (D) of the tree’s branch spread and add one-half (D) to determine the area’s dimensions (see illustration). If (D) is 24 feet, then 11/2 times 24 feet equals 36 feet on each side. The area to fertilize is 36 feet by 36 feet or 1,296 ft2 (round to 1,300 ft2). 1. Next, determine the amount of actual nitrogen (N) to apply based upon the treatment area. At a rate of 3 lbs actual nitrogen per 1,000 ft2, 3.9 lbs of N is needed for 1,300 ft2. (See table below.) 2. Finally, determine the pounds of fertilizer to apply. To do this, divide the amount of actual nitrogen (N) to apply by the percentage of nitrogen in the fertilizer. 1. 2. 3. 4.

Treatment Area (ft2) 700 1,000 1,300 1,600

1. 2. 3. 4.

Amount of Actual Nitrogen (N) to Apply at 3 lbs/1000 2.1 lbs. 3.0 lbs. 3.9 lbs. 4.8 lbs.

1. 2. 3. 4.

Using 20-5-5 Apply 10.5 pounds of fertilizer Apply 15.0 pounds of fertilizer Apply 19.5 pounds of fertilizer Apply 24 pounds of fertilizer

1. 2. 3. 4.

Using 12-12-12 Apply 17.5 pounds of fertilizer Apply 25.0 pounds of fertilizer Apply 32.5 pounds of fertilizer Apply 40.0 pounds of fertilizer

Source: http://www.mortonarb.org/trees-plants/tree-and-plant-advice/horticulture-care/fertilizing

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