Planting Street Trees
What's a street tree? In Seattle, street trees are regulated by the Seattle Department of Transportation (SDOT). A street tree is planted in the public right-of-way, usually in the planting strip (space between sidewalk and road) or in the absence of sidewalks, in the space approximately 10 feet from the curb or roadside. If the greenspace adjacent to your property is an unimproved right of way (an area originally set aside for alleys, streets, or paths that has not been developed), then a tree planted there would be considered a street tree. Trees in greenspaces owned by Seattle Parks and Recreation are not considered street trees.
The City of Seattle encourages residents to plant trees along public streets, with a permit from the Seattle Department of Transportation's (SDOT) Arborist Office. Once you've been approved for a permit to plant, you will be responsible for properly planting and maintaining the tree, which includes watering during the hot summer dry season, mulching and pruning.
Planting a tree in the planting strip or right-of-way requires special consideration of underground and overhead utilities, tree species, and planting strip width. When planting street trees, we want to avoid future conflicts between trees and utility lines and also minimize any impacts to traffic along the street. This is why SDOT requires residents first obtain a free street tree planting permit before planting. The great thing about applying for a permit is that an SDOT arborist will review your tree selection and site and make recommendations, if necessary.
6 Steps to Street Tree Planting
Planting your tree in the fall gives it the best chance for survival. Allow time to evaluate your site, select the right tree for the space, and complete the permit process. Start planning in spring to be ready to plant in fall.
1) Identify Your Planting Site. First look for overhead power lines. Sites with overhead power lines need a tree that will grow to less than 25 feet at maturity. Measure the width of your planting strip - it needs to be at least 4 feet wide to plant a tree. [If your planting strip is less than 4 feet wide, you can still garden in your planting strip as long as vegetation is less than 30 inches tall.]
Your tree selection depends completely on the width of your planting strip. Finally, evaluate the surrounding infrastruture in the area and choose a planting site that is a safe distance away.
SDOT requires street trees be planted to the following standards:
- 3 ½ feet back from the face of the curb
- 5 feet from all underground utility lines (Call 811 to locate lines)
- 10 feet from power poles
- 7 ½ feet from driveways (10 feet recommended)
- 20 feet from street lights and other existing trees
- 30 feet from street intersections (avoid driver sightline issues)
2) Select Your Tree. Choose a species appropriate for your planting strip width, and under 25 feet at maturity if planting under power lines.
Fruit trees cannot be planted along streets because fallen fruit creates a slipping hazard. Big leaf maple (Acer macrophyllum), cottonwood (Populus trichocarpa) and Lombardy poplar (Populus nigra) are banned as street trees because of their aggressive roots. Choosing the largest species appropriate for your site will allow your tree to contribute the greatest benefits.
For a list of street trees appropriate for your neighborhood, please send your request to firstname.lastname@example.org.
3) Apply for a Free Planting Permit. Contact SDOT at (206) 684-TREE, email Seattle.Trees@Seattle.gov or visit SDOT's website to fill out the urban forestry permit application (Permit Use Code 1A) and send to email@example.com.
4) Locate Underground Utilities (Call 811). The law requires you to locate underground utilities by calling 811 or submitting an online dig ticket prior to planting your tree. Visibly mark your proposed planting location in white paint and then call 811 to submit your dig ticket. Call 811 before an SDOT arborist arrives for the inspection.
Note: your sewer line will not be marked. Use this tool to locate your side sewer line and always plant at least 5 feet away.
5) Wait for a Permitting Decision. An SDOT arborist will visit your site and consider the proximity of other trees in the area, underground and overhead utilities, and other structures. Not all locations are suitable for a tree. If your street tree permit is denied, SDOT will inform you of their permitting decision.
6) Plant & Care for Your New Street Tree. Upon permit approval, you are ready to plant your new tree! You are responsible for all future maintenance and tree care, including watering during the hot summer dry season, mulching, pruning, and protecting your tree from mechanical damage. Learn more about planting and care here.
Street Tree Removal/Replacement
You must receive a permit from SDOT before removing any street tree. According to SMC 15.43.030 C, a street tree can only be removed if:
- It is a hazardous tree.
- It poses a public safety hazard (that cannot be corrected unless the tree is removed).
- It is in such a condition of poor health or poor vigor that removal is justified; or
- It cannot be successfully retained, due to public or private construction or development conflicts.
If SDOT determines your tree meets these criteria, a removal notice will be posted on the tree for 10 days to allow for public notification. A removal permit will be issued following the public notification period. Removing a street tree without a permit can result in a $500 citation, and additional penalties may apply.
For more information on applying for a removal permit visit SDOT’s website at www.seattle.gov/transportation/treeplantapp.htm or call 206-684-TREE (8733).
Links & Resources
SDOT's Street Tree Manual is an excellent resource for residents, developers, contractors, and tree service providers. This manual outlines the requirements and standards established in the 2013 Street Tree Ordinance. For questions about this manual contact SDOT at (206) 684-TREE or Seattle.Trees@seattle.gov.
SDOT Street Tree Planting Permit
Choosing the Right Tree when Planting Under or Near Power Lines
SDOT's Online Street Tree Map
Registered Tree Service Providers
Master Street Tree List - Includes small, medium, and large trees for the planting strip and minimum planting strip width requirements
Want help planting street trees? Consider participating in the City of Seattle's Trees for Neighborhoods project.