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Noxious weeds

King County, Washington

To offer a suggestion or report an error on the King County Noxious Weeds website, please contact Sasha Shaw, education specialist.

Class Schedule

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2014 Noxious Weed Control Seminar

Session Dates and Locations

Cost:  Free (pre-registration required)
How to sign up: Register online
Credits:  5 WSDA Pesticide License Recertification Credits

Presenters: The 2014 agenda features noxious weed control identification and control tips from the county's noxious weed specialists and live weed specimens on display, as well as special guest presentations by plant ecologist Clay Antieau from Seattle Public Utilities and biological control expert Jennifer Andreas from WSU Extension.

Note the new extended time for 2014.  There will only be a 30 minute break for lunch, so make sure to bring a sack lunch or enough snacks to tide you over until 1:30 pm.

All sessions have the same agenda, but immediately following the North Session, there will be a separate Knotweed Control Workshop (see below; register for each separately).

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2014 Knotweed Biology and Control Workshop - two sessions!

Session 1 - Kenmore - SESSION IS FULL
 May 14, 1:45-3:30pm
LocationNorthshore Utility District, 6830 NE 185th St., Kenmore, WA 98028

Session 2 - Preston
June 4, 9:00 am to 11:00 am
Location: Preston Community Center, 310th Ave SE and Preston Fall City Rd SE, I-90 Exit 22, Preston, WA 98027

Cost:  Free (pre-registration required)
How to sign up: Register online
Credits:  2 WSDA Pesticide License Recertification Credits

Presenters:  Frances Lucero and Sasha Shaw, King County Noxious Weed Control Program

This workshop will cover invasive knotweed identification, biology, and control. Included in the chemical control section, we will give instructions on the use and care of knotweed injection guns.

Knotweed Injectors:  Individuals completing this workshop will be eligible to borrow the county weed program’s injection guns.

NOTE:  The Kenmore session of this workshop is being held immediately after the North Session of our annual noxious weed control seminar (see above for more information). If you would like to attend both the noxious weed seminar and the knotweed workshop in Kenmore, please register for each separately.

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What is Knotweed and How Can I Get Rid of It?

All sessions are from 6:30 pm to 8:30 pm and have the same agenda:

Invasive knotweed is one of the toughest weed thugs around and it is becoming all too common in King County. It chokes out everything else, increases erosion and overwhelms riverbanks. Fighting it is frustrating without effective methods and tools.

This workshop will explain why this plant is so tough to stop and what it takes to control it.


  • How invasive knotweed grows and spreads
  • How and where to use different methods to control knotweed
  • How to borrow a knotweed stem injector for use on your own land
  • What is being done to fight knotweed on rivers in King County

Staff from the King County Noxious Weed Control Program will teach how to identify knotweed, how and where it grows, and how to control it effectively using a variety of different methods.

This is a hands-on workshop with practical control tips. Participants will be eligible to borrow the program’s knotweed stem injectors for use on their own knotweed.

Free and open to the public. Register online. WSDA license recertification credits will be available.

The King County Noxious Weed Control Program offers workshops and presentations upon request for community groups, neighborhood councils, vegetation management professionals, volunteer events, garden clubs and a wide range of other groups. Please contact Sasha Shaw if you would like a presentation on invasive plants or noxious weeds for your group, staff or community.

Related information

Related agencies

Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. To contact staff, see the Noxious Weed Control Program Directory, send an email, or call 206-477-WEED (206-477-9333).