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Invasive Plant Rules in Seattle, WA (2026)

1 verified invasive plant rules for Seattle, Washington, sourced directly from the municipal code and official government pages.

Verified from official government sources

Prohibited Species

Seattle follows the Washington State Noxious Weed List and King County's noxious weed regulations. Property owners must control Class A, B, and C noxious weeds. Common prohibited species include knotweed, Scotch broom, English ivy, and Himalayan blackberry.

Prohibited Plant Species in Seattle

Some Restrictions

RCW 17.10 / WAC Chapter 16-750 — Washington's Noxious Weed Laws (Classes A, B, C)

The State's Noxious Weed List is Organized into Three Classes of Weeds: Class A, B, and C. Class A Weeds — Class A weeds are mostly newcomers to Washington, and are generally rare. The goal is to completely eradicate them before they gain a foothold. Landowners are required to completely eradicate Class A weeds. (Eradicating weeds means getting rid of the plants altogether, including plant root...

Looking for King County county-wide rules?

County ordinances apply to unincorporated areas and may supplement Seattle city rules.

Invasive Plant Rules in King County