Noxious weeds in King County, Washington
COVID-19 Update
The King County Noxious Weed Program office is currently closed to the public and employees are working from home. The program is continuing to perform critical noxious weed survey and control work to protect human and environmental health. Noxious weed program staff are available to help through email or by calling 206-477-9333. To learn more about COVID-19, visit kingcounty.gov/covid.
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
- Answers to frequently asked questions about noxious weeds, property tax assessment, King County Weed Board, and more
- Weed lists and laws - King County Weed List, definition of noxious weed, Washington State Weed Law
- Fact sheets, brochures, reports and publications - Download weed fact sheets, brochures, slideshows and reports (publicaciónes en español)
- Classes and workshops - calendar and descriptions of upcoming noxious weed classes
- Webinars on demand - watch recordings of past noxious weed classes and seminars on our YouTube playlist
- Upcoming classes - look for upcoming classes and sign up on Eventbrite
- Knotweed control videos - learn how to control knotweed and borrow a stem injector
- Fairs and events calendar - calendar of noxious weed information booths; experts will be on hand at these events
- Healthy Lands Project - resources and events for conservation and stewardship
- School resources - free classroom programs available for schools in King County
- Noxious Weeds blog - Weed of the Month, weed control tips, 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 noxious weed in King County, Washington with our web form or mobile app. We need your help to find early infestations while we still have a chance to stop them, and to learn more about where weeds are impacting people and the environment in King County.
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
Participate
- Join the King County Noxious Weed Control Board
- Share your ideas and feedback at a public Board Meeting
- 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.
Languages
Find information on noxious weed identification and control in multiple languages:
Sign up for KC Weed News
Report Noxious Weeds
Get the app King County Connect
Languages
Find information on noxious weed identification and control in multiple languages:
News and announcements
Noxious Weed News - Noxious weeds blog for King County including Weed of the Month, weed control tips, events, and news on noxious weeds
2021 online classes open for registration
2021 King County Noxious Weed List is official
I dream of knotweed: the Water and Land Resources Division at work
Frequently asked questions
- What are noxious weeds?
- How do I report a noxious weed?
- Why is there a noxious weed fee on my tax bill?
- 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?
- More . . .
Related information
- Invasive species in King County, Washington
- Northwest native plant guide
- Agriculture in King County, Washington
- Northwest yard and garden
- Animals, plants and habitat