Restoring the Urban Forest

Volunteers removing invasive species

Invasive species are damaging Seattle's urban forest by smothering trees and taking away growing space for native and beneficial understory plants. By nature, invasive plants are aggressive and take over landscapes and smother native and non-invasive ornamental plants. In 2017, it was estimated that the economic impact of the 23 most damaging invasive species in Washington totaled $1.3 billion a year and a loss of 8,000 jobs.

English ivy and invasive blackberries are both widespread in Seattle parks and yards. Ivy grows quickly up the trunk of a tree, smothering branches, and eventually killing the tree. Ivy also robs nutrients from trees and provides a haven for rats in urban yards. Invasive Himalayan and evergreen blackberry out-compete native understory plants and prevent the natural regeneration of native trees that require sun for germination.

Invasive plants on residential property do not just degrade the landscape around homes, but also provide the seed source for the invasive plants that invade Seattle’s public spaces. Thousands of volunteer hours have gone into removing invasive species from parks through the Green Seattle Partnership, however until the worst invaders are eliminated on residential property, the seed source will continue to infest parks.

Ways You Can Help

Explore the following links to learn more about how we can all work together to control invasive species in Seattle. A Certified Ecological Restoration Practitioner (CERP) may be able to help.

Remove invasive species from your own yard. Saving Seattle's urban forest starts in your backyard!

Join a Tree Ambassador work party and help remove English ivy and other aggressive weeds from landscapes in your neighborhood. Check out upcoming opportunities on our events page.

Volunteer with Green Seattle Partnership: This partnership between the City of Seattle and Forterra has the goal of restoring and maintaining Seattle’s urban parks and natural areas. Join a volunteer event in a park near you.

Identify and remove invasive plants: Use King County Noxious Weed Program's Noxious Weed Identification Tool to identify weeds in your yard or read about Seattle's most common weed offenders: