Comprehensive Street Tree Plan
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COMPREHENSIVE STREET TREE PLAN CITY OF TUMWATER September, 2002 Prepared as a cooperative effort between WASHING TON FORESTRY CONSULTANTS, Inc., the CITY OF TUMWATER, and the WASHINGTON DEPARTMENT OF NATURAL RESOURCES COMPREHENSIVE STREET TREE PLAN CITY OF TUMWATER SEPTEMBER, 2002 Prepared for the City of Tumwater by Galen M. Wright Certified Arborist/Certified Forester Washington Forestry Consultants, Inc. Olympia, WA 360/943-1723 TABLE OF CONTENTS Executive Summary Introduction 1 Goals of the Comprehensive Street Tree Planning Process 2 The Street Tree Planning Process 3 Current Tree Conditions 6 Street Tree Themes 15 Street Profiles for Trees 26 Planting Space Recommendations 27 Street Tree Planting and Maintenance 29 Ordinance Review 36 New Tree Ordinance - Public Tree Maintenance 37 Urban Forest Management Plan 37 Appendix I - American National Standard for _Nursery Stock 38 Appendix II - Tree Planting Specifications 39 Appendix III - Tree Pruning Guidelines for Small Trees 40 LIST OF TABLES AND FIGURES Figure 1. Ideal street profile for trees with median. 24 Figure 2. Ideal street profile without median. 24 Figure 3. Common street profile in Tumwater. 25 Figure 4. Common residential street profile in Tumwater. 25 Figure 5. Minimum street profile for planter strips. 26 No #. Street tree planting detail. 28 Figure 6. Calendar for tree planting and maintenance activity. 32 Table. 1 General List of Trees for Tumwater 13 Table 2. Street Tree Themes for Tumwater Arterials and Collectors 21 Map of Tumwater Arterials and Collectors 23 Executive Summary An evaluation of the Tumwater street profiles and street trees found that less than 5% of the available planting space along arterials and collectors to be stocked with planted street trees. Many gaps in planters and spaces behind sidewalks are empty or stocked with low growing plants. The flowering plum, which dominants the street tree population is a short-lived tree that is reaching maturity. The tree lined street with canopy forming trees as depicted above, does not yet exist in Tumwater. This study has provided a comprehensive list of street trees, accent trees, and utility friendly trees for all of Tumwater's arterials and collectors, as well as a general list for landscaping purposes. A prescription for tree planting and maintenance was developed for Tumwater, along with a detailed tree planting specification for use in public works and parks projects. The tree planting plan, specifications, and maintenance guidelines should help ensure that the durable, long-term, canopy forming trees will be planted along city streets, forming the linkages between zones of the city. Selected areas were prioritized for the initial re tree efforts. Though this plan will be long-term, our efforts today should greatly enhance the quality of appearance of the streets, and the city of Tumwater. COMPREHENSIVE STREET TREE PLAN City of Tumwater Introduction The City of Tumwater's "physical and aesthetic character" will be preserved and enhanced with a long-term plan providing street tree 'themes' and space for trees. This street tree plan, coupled with creative landscape plantings and preservation of native trees in new developments, parks, critical areas, open spaces, and residential lots will insure that the environmental health, economic, and aesthetic benefits of trees to a community grow with time. The stature of tree planting in the city was elevated by the late Stanley Foss Bartlett who wrote: Whoever planted rows of trees Beside the roads and lanes, God rest his soul in Heavenly peace And bless him for his pains; For he who gave of time and toil, Who gave of heart and hand To nurse the tender shoots that were To shade the ways of man, Was quite as great as those who built Of stone and minted gold - No need to cast his name in bronze, His deeds need not be told. Tumwater Comprehensive Street Tree Plan Trees are one of the most useful design elements on individual projects, but must be planned on a community wide basis so that diverse elements of the entire city are linked. This linkage cannot possibly be achieved if urban forestry planning proceeds on a project by project basis. Space for trees must be created to achieve the long-term benefits that trees provide for the entire community. Goals of the Comprehensive Street Tree Planning Process The following are the goals of the street tree planning process: 1. Modify street standards to provide space for trees. 2. Modify street tree design and planting guidelines to provide for long-term development and health of the trees. 3. Update the tree selection list to provide durable, long-term street trees. 4. Require street trees to be planted on all public and private streets, and in all new industrial, commercial, and residential development. 5. Provide the budget necessary to maintain street trees. 6. Aggressively solicit funding to bring existing major and minor arterials up to this long-term plan. Photo A. The Goal: Streets lined with canopy forming trees (City of Milwaukee, WI). Washington Forestry Consultants, inc. 2 Tumwater Comprehensive Street Tree Plan The Street Tree Planning Process The process of street tree planning encompasses all aspects of street design, soils and tree biology, planting, maintenance, and ordinances that affect street trees. Planting Design Patterns (Themes) There are four general designs for planting trees in the community. The type of design depends upon space available, both above and below ground, presence of other native tree stands, the character of the area, and effect desired. 1. Formal Design: This approach is strongly advocated to provide spatial definition to street corridors, and continuity between different types of areas within the city. This type of planting scheme works well in grid type street designs and long, linear corridors that lack space for groupings of trees. Trees are normally planted in rows. Species diversity is usually limited, but not so limited that monocultures are created. 2. Informal Design: This approach utilizes clustering, planting a variety of species, with irregular spacing intervals by design, or because of space limitations. This design is more often applicable in suburban areas, or newly developing areas where space can be created on and off of rights-of-ways for tree plantings. It can however, be used in virtually every zone of the city achieving more species diversity. Informal plantings are most common in parks, and along park corridors. 3. Combined Design: In some cases, informal plantings can be used to break-up the more formal rows of trees, where space is provided. This is especially useful in commercial and industrial areas to help break up the moonscape of asphalt and buildings. Plant size, shape, color, seasonal flowering, fall coloration and growth rates are the most critical factors to consider when combining planting designs. 4. Wildlife Design: This concept utilizes clusters, layers of vegetation, and a variety of species of trees and shrubs to attract songbirds and small mammals. This design is best utilized near critical areas or other open spaces, and in parks. Safety and security must be considered when created these types of dense plantings. Most trees with higher value for wildlife trees, are not suitable for the street environment due to size, form, or fruit production. Mature Tree Size Street tree plantings are limited by space. Large trees require wide planter strips or areas for the tree roots to explore to avoid damage to curbs, sidewalks, and underground utilities. Powerlines, adjacent buildings, overhanging awnings, and vehicle clearances are the most common above ground restrictions to growing space. Planting a tree with space to achieve its mature size will greatly increase the aesthetics and useful life of the street tree, while dramatically reducing the maintenance costs. Washington Forestry Consultants, Inc. 3 Tumwater Comprehensive Street Tree Plan Longevity of the Species Communities must fight the urge to plant fast growing tree species such as soft maples, poplar, and birch. Generally the fast growing tree species have shorter life-spans, are more easily damaged by storms, and cause more damage to curbs and sidewalks. This results in higher maintenance costs, requires replacement of trees years sooner, and upsets the visual and spatial continuity of the planting. Species such as Norway and sugar maple, linden, northern red and other oaks, and ash species tend to be more durable long-term trees. Tree Character The color of summer and fall foliage, presence of flowers, shape of the crown, color of bark, type of foliage, and habit of branches (weeping, upright) give trees their color, texture, and form. These characteristics, along with size, longevity and growing space should be considered when selecting trees for all projects. These tree characteristics should complement building architecture, define streets and sidewalks, accent adjacent landscaping, and add diversity along Tumwater streets. Trees are defined as having form that is: 1. Columnar 2. Round- full crowned, or spreading (upright, oval, globose) 3. Pyramidal (conical) 4. Vase shaped 5. Weeping 6. Irregular 7. Multi-stemmed 8. Fountain Multi-stemmed trees are less desirable for street trees due to line-of-sight obstruction and sidewalk clearances. In most cases, tall growing trees are best since it is easy to raise crowns for ground and vehicle clearances. Signs for adjacent businesses can be exposed by crown raising. Ground signs work well with trees. Washington Forestry Consultants, Inc. 4 Tumwater Comprehensive Street Tree Plan I J pyramidal full-crowned fountain ··y. I: weeping columnar spreading vase-shaped multlstemmed Illustration of Tree Shapes. The form is critical in selecting trees to fit the growing space, and providing amenities such as screening of incompatible land uses or unsightly buildings, protecting views of vistas or signs, or lining streets in formal designs. The summer color of a tree generally includes hues of green or shades of red or maroon.