Welcome to the Thurston County Noxious Weed Control Website!

Contact Information

9605 Tilley Rd. S. Bldg B
Olympia, WA 98512

(360) 786-5576



Public Works

Jennifer Walker, Department Director and liaison to the Board of County Commissioners

Thurston County Noxious Weed Control Board Members:

Carol Piening, Chair
Fran Sant, Vice Chair
Paul Thomsen
David Mills

WSU Thurston County Extension
Stephen Bramwell, Director

Noxious Weed and Lake Management Staff

 Tim Wilson, Manager
Mary Jo Seery, Noxious Weed Specialist II

Mike Murphy, Noxious Weed Specialist II

Paula Cracknell, Aquatic Resource Specialist

Angela Celestine, Senior Office Assistant


Our mission is to protect the citizens, the natural resources, and the agricultural resources of the County from the degrading impact of invasive, noxious weeds.


Noxious weeds threaten public health, the environment, wildlife habitat, native plants, agriculture areas, and recreational areas.

Thurston County Noxious Weed Control is monitoring for 40 species of noxious weeds which are targeted for control out of a list designated by the State of Washington, which are known to exist in Thurston County. Species that have not yet been found in Thurston County, are targeted annually through early detection surveys.This preventative effort to find species while they are limited prevents them from becoming widespread. Prevention is the most effective control strategy. All species of noxious weeds are non-native.

A risk assessment is used in prioritizing the weed list. To view our rationale, go to the Risk Assessment Chart. To see photographs of those species designated for control in Thurston County, go to the Noxious Weed List.

Species of Concern

In addition to the species listed on the County noxious weed list, six species pose a significant threat due to their invasive traits: spartina, kudzu, garlic mustard, hydrilla, water primrose and flowering rush. These species are not yet found in Thurston County.

In addition to the species listed above, there are weeds of special concern because of their aggressive and invasive natures.These species are already known to be widespread in Thurston county. These include:

Evergreen blackberry (Rubus laciniatus), Himalayan blackberry (Rubus armeniacus), Eurasian watermilfoil (Myriophyllum spicatum), Policeman’s Helmet (Impatiens glandulifera), Canada thistle (Cirsium arvense), Scotch broom (Cytisus scoparius), yellow nutsedge (Cyperus esculentus), and the invasive cultivars of English Ivy: Hibernica” (Hedera hibernica), “Baltica” (Hedera helix), “Pittsburg” (Hedera helix) and “Star” (Hedera helix). 

Disposal of Noxious Weeds

  • Some problem weeds such as Knotweed, Scotch broom, blackberry and English Ivy are not on Thurston County's list for free disposal, but are of concern to citizens.Click here to find out what do to with other bad weeds.

Thurston County Noxious Weeds Map

Thurston County Weeds Map

Click the image above to go to the Noxious Weeds Map on the Thurston County Geodata web site. Use this map to see which known noxious weed species are in your neighborhood. Here's how:

  • Select the search tab to find your property either by address or parcel number.
  • Select the layers tab, under miscellaneous on the list of possible layers, check the box next to the noxious weed layer to turn on.
  • Known noxious weed species symbols will then appear, use the legend tab to identify symbols of the species of noxious weeds that are depicted.

Contact Us

Address questions or comments to: tcweeds@co.thurston.wa.us