Welcome to the Thurston County Noxious Weed Control Website!

Contact Information

11834 Tilley Rd. S.
Olympia, WA 98512

Location Map

(360) 786-5576



Public Works

Ramiro Chavez, Department Director and liaison to the Board of County Commissioners

Thurston County Noxious Weed Control Board Members:

Gene Little, Chair
Martin Casey, Vice Chair
Jeff Grimm
Patricia McCann
Dorothy Saunders

Noxious Weeds & Lakes Staff

Rick Johnson, Coordinator
Mary Jo Seery, Lead Weed Technician
Janie Civille, Aquatic Resource Specialist
Dan Reynoldson, Weed Technician
Angela Celestine, Office Assi


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 42 species of noxious weeds which are targeted for control out of a list of 99 designated by the State of Washington. The remaining 57 species have not yet been found in Thurston County, but 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). 


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

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