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Thurston County, Washington

The content on the Thurston County website is currently provided in English. We are providing the “Translation” for approximately 10 languages. The goal of the translation is to provide visitors with limited English proficiency to access information on the website in other languages. The translations do not translate all types of documents, and it may not give you an exact translation all the time. The translations are made through an automated process, which may not result in accurate or precise translations, particularly of technical and legal terminology.

Public Works

Garlic Mustard Weed

The following is a list of species known to be present or have the potential to infest Thurston County. It is approved and updated annually by the Thurston County Weed Board.

Noxious Weed Classifications

• species new to the state 

• limited distribution throughout state  

• goal is to eliminate before established  

• landowners required to control

• widespread in parts of state, limited or absent in other parts of the state 

• goal is to prevent spread into new areas and contain or reduce existing populations  

• the state designates Class B noxious weeds in certain areas 

• a county weed board may select Class B noxious weeds for control in the county  

• landowners required to control Class B designate and Class B select noxious weeds  

• control of all other Class B noxious weeds not required but recommended

• often widespread, or of special interest to agriculture  

• a county weed board may select a Class C non-designate for control if it is considered a local priority 

• control of all other Class C noxious weeds not required but recommended

The noxious weeds below only includes weeds from the Noxious Weeds List which have been found in Thurston County. For a printable list of all species regulated by Thurston County, click here

Noxious Weeds Fact Sheets

​Scientific Name Egeria densa - Fact sheet awaiting approval

Photo of Brazilian elodia

​except variety, azoricum

Scientific Name | Foeniculum vulgare

photo of common fennel

​(nonnative genotypes of)

Scentific Name | Phragmites australis

Photo of common reed

​Scientific Name | Euphorbiaoblongata - Fact sheet awaiting approval

Photo of eggleaf spurge

​Scientific Name | Alliaria petiolate - Fact sheet awaiting approval

Photo of garlic mustard

​Scientific Name | Carex pendula - Fact sheet awaiting approval

Photo of hanging sedge

​Scentific Name | Carduus pycnocephalus -Fact sheet awaiting approval

photo of Italian thistle

​Scientific Name | Ficaria verna - Fact sheet awaiting approval

photo of lesser celandine

​Scentific Name | Cortaderia seloana 

Control is required in Township 18 N, Range 2W, Section 10 and on all transportation and utility rights of way, public land and gravel mines.

photo of pampas grass

Scentific Name | Geranium Lucidum

To be controlled on Thurston County property, gravel mines, heavy equipment storage areas and those rights of way that may directly or indirectly spread seed or contaminated material in wildlife refuges, nature preserves or other high quality habitat areas.

photo of shiny geranium

​Scentific Name | Carduus tenuiflorus - Fact sheet awaiting approval

photo of slenderflower thistle

​Scentific Name | Potentilla recta

Control is required on transportation rights of way in all of Thurston County and on all other land except that portion of Thurston County East of Range 1 East and South of Township 17 North.

photo of sulfur cinquefoil

​Scentific Name | Jacobaea vulgaris

Control is required when 25 or more plants are present in an area of 20 acres or less. This area may include more than one parcel if the area is under the same ownership. Priority will be given to property in agricultural areas, particularly where livestock is present.

photo of tansy ragwort

​Scientific Name | Myriophyllum heterophyllum - Fact Sheet awaiting approval

photo of variable-leaf milfoil

​Scientific Name | Hieracium murorum -Fact sheet awaiting approval

photo of wall hawkweed

Scientific Name | Iris pseudacorus - Fact Sheet awaiting approval

Deep Lake, Lawrence Lake, transportation rights-of-way and Thurston County Property only

photo of yellow flag iris

Scientific Name | Hieracium caespitosum - Fact sheet awaiting approval

photo of yellow hawkweed