#56 – Urban Forestry

Seattle, Washington

Shane DeWald, Landscape Architect
Liz Ellis, Program Manager
Peter Lagerwey, Pedestrian and Bicycle Program



Certain tree species are not recommended or are even prohibited due to fruiting characteristics, brittle wood or root growth traits.

Landscape guidelines, such as set back and pruning requirements, help maintain visibility and a safe multi-modal environment while the trees contribute to a healthier, more aesthetically pleasing environment.

The mission of Seattle’s Urban Forestry Program is to administer, maintain, protect and expand the city’s urban landscape in street rights-of-way for Seattle’s residents and businesses so that environmental, aesthetic, and safety benefits are maximized. Most of Seattle’s trees are less than 30 years old and more than 50,000 new trees have been planted in the past 10 years through various city programs. The Urban Forestry Program is part of the city’s effort to create a better bicycling and walking environment, to provide a buffer between vehicular and pedestrian traffic, thereby improving comfort and safety, to discourage vehicular parking on planting strips, and to improve air and water quality. When combined with other treatments, street trees also contribute to speed management on residential and arterial streets, creating a better bicycling and walking environment. The posted speeds of most arterial streets in Seattle are 30 or 35 miles per hour.


New trees get planted in a variety of ways. They are routinely included in roadway reconstruction projects and sidewalk projects, and are required as part of the development or redevelopment of property. Trees are installed as part of neighborhood tree planting projects, planted by individuas, and the Urban Forestry Program has some funds to plant trees on targeted arterials.

The success of the Urban Forestry Program can be attributed to the successful partnership between the city and the citizens of Seattle, to maintain, protect and expand the trees in Seattle’s street rights-of-way.

Steward Program

Seattle’s Steward Program trains residents to help care for street trees. Classes on tree maintenance and planting are provided. Residents are trained to take inventory of the trees, to seek planting opportunities in their neighborhood and to organize neighborhood tree-planting projects.

Heritage Tree Program

Since 1996, Seattle has listed 20 trees with the Heritage Tree program. Heritage trees may be on either City or private property and must have the owner’s approval. Trees can be recognized for their size, age, historic association with a place or event, or be a community landmark. Each tree is identified by a plaque and is part of a Heritage tree tour.

Citywide Traffic Circle Garden Contest

The landscaping on Seattle’s traffic circles is maintained by nearby residents. Every year, there is a citywide contest to determine the best-maintained traffic circles. Up to 10 awards are given each year, often with good media coverage.

More information, including tree selection and planting guidelines, is available at the Seattle Urban Forestry Web site at http://www.seattle.gov/transportation/treeplanting.htm.

Evaluation and Results

The Urban Forestry Program is evaluated by the health and survival rate of trees, the level of public involvement by the Steward and other programs and the number of new trees planted.

The Urban Forestry Program is a success by all measures. The city has been recognized by the national Arbor Day Foundation as a Tree City USA for 16 years and as a Tree Growth City for nine. Public involvement has been and continues to be high and over 50,000 new trees have been planted in the last 10 years.

Conclusions and Recommendations

After years of focused efforts to maintain, protect and expand the city’s urban landscape in street rights-of-way, the program has been successful in making Seattle a more livable, walkable, and bikeable community. The results include improvements in aesthetics, safety and air quality that benefit all road users. Additionally, Seattle residents enthusiastically support the program through their volunteer efforts.

Costs and Funding

Multiple funding sources acquired through “piggybacking” on other projects and volunteer contributions.


Nolan Rundquist
City Arborist
Seattle Department of Transportation
700 5th Avenue, Suite 3900
P.O. Box 34996
Seattle, WA 98124-4996
(206) 615-0957

Shane DeWald
Landscape Architect
Seattle Department of Transportation
700 5th Avenue, Suite 3900
P.O. Box 34996
Seattle, WA 98124-4996
(206) 684-5041

Liz Ellis
Program Manager
Seattle Department of Transportation
700 5th Avenue, Suite 3900
P.O. Box 34996
Seattle, WA 98124-4996
(206) 684-5008