Noxious weeds in King County
Noxious weeds are a danger to our environment and the economy. These introduced species cost our region millions of dollars in lost agricultural production, environmental degradation and added maintenance costs. Once invasive plants spread to natural areas, they harm native plants and wildlife and can be impossible to eradicate.
Identify and learn about weeds and invasive plants
- Photo guide and index to weed information pages - Look up specific weeds to learn about each plant's impacts, growth, control methods and identification
- Weed lists and laws - King County Weed List, definition of noxious weed, Washington State Weed Law
- Brochures and publications - Download weed fact sheets, brochures, slideshows and reports (publicaciónes en español)
- Noxious weed classes - calendar of upcoming noxious weed classes
- Fairs and events calendar - calendar of noxious weed information booths; experts will be on hand at these events
- School resources - free classroom programs available for schools in King County
- Noxious Weed News - Visit our blog for the Weed of the Month and other timely information, news and updates
Locate noxious weeds in King County
- Maps - view the spread of noxious weeds in King County - see where noxious weed infestations have been found near your location
Report an infestation
- Report a regulated noxious weed (only for locations in King County, Washington)
- Please help us locate regulated Class A, B, and C noxious weeds in King County so we can work with the property owners and public agencies responsible to ensure the weeds are controlled effectively. We need your help to find early infestations while we still have a chance to stop them.
- Contact us for more info on non-regulated weeds
Control noxious weeds
- Best Management Practices and Regulatory Guidelines
- Weed control tips - how to control weeds, Best Management Practices, Integrated Pest Management
- Knotweed control video - four short videos on knotweed control techniques, including stem-injector instructions
- Become a weed watcher - volunteer to spot invasive plants in remote areas and on lakes before they become established
- Volunteer to fight invasive weeds and restore parks
To contact us, please see the staff directory for the King County Noxious Weed Control Program, call 206-477-WEED (206-477-9333) or send us an e-mail. Program offices are located in the King Street Center Building at 201 S. Jackson St., Suite 600, Seattle, WA 98104.
Sign up for KC Weed News
News and announcements
Noxious Weed News - Noxious weed blog for King County including Weed of the Month, weed tips, events, and news on noxious weeds
Landowners: Time to control toxic tansy ragwort and keep horses, cattle safe. King County Press Release. July 11, 2016.
King County Executive Proclamation. National Invasive Species Awareness Week February 21-27, 2016.
King County urges landowners to watch for deadly noxious weeds this spring. King County Press Release. April 2, 2015.
King County’s noxious weed list has growth spurt with addition of 4 new garden escapees. King County Press Release. Jan 8, 2015.
Beware of the Giant Hogweed, the invasive plant that can cause burns and blisters. KPLU.org. May 12, 2014.
City People's Garden Store first in King County to commit not to sell invasive plants, noxious weeds. King County/City of Seattle Press Release. April 9, 2014.
Frequently asked questions
- What are noxious weeds?
- How do I report a noxious weed?
- Who is responsible for noxious weed control?
- How do I know what weeds I have?
- How do I control noxious weeds?
- What is the King County Weed Board?
- Why is there a noxious weed fee on my tax bill?
- More . . .
- Invasive species in King County, Washington
- Northwest native plant guide
- Agriculture in King County, Washington
- Northwest yard and garden
- Animals, plants and habitat