Weed Laws

The term "noxious" is a legal term, rather than botanical or technical. It is used to describe non-native plants that have been introduced to Washington from other parts of the world and have a damaging impact on the local industries that rely on having a healthy ecosystem and plant community, such as agriculture, etc. Because of their aggressive growth and lack of natural enemies in the state, these species can be highly destructive, competitive, or difficult to control. Noxious weeds can reduce crop yields, destroy native plant and animal habitats, severely limit recreational opportunities, clog waterways, lower land values, create problems with erosion, fire hazards, and even poison humans or livestock.

Cooperation with landowners and the public is integral to the management of noxious weeds. It is the desire of the Lewis County Noxious Weed Control Board that everyone look beyond jurisdictional boundaries and take an active role in the management of noxious weeds and the stewardship of Lewis County. It takes a community-wide effort!

Lewis County Noxious Weed Control Board carries out the mandates of the Washington State Weed Law RCW 17.10. The weed law was instituted to control the introduction and spread of invasive, non-native plants that threaten our local resources. The primary responsibility for noxious weed control is placed on the landowner, whether private, state, or county lands (federal lands are not subject to state or local ordinances). For more information see the links below:

Washington State Noxious Weed Control Board

Chapter 17.10 RCW

Chapter 16-750 WAC

Definitions from the WA State Noxious Weed Control Board website:

Class A Weeds

  • Class A weeds are mostly newcomers to Washington, and are generally rare. 
  • The goal is to completely eradicate them before they gain a foothold.
  • Landowners are required to completely eradicate Class A weeds (Eradicating weeds means getting rid of the plants altogether, including roots and all other parts).

Class B Weeds

  • Class B weeds are those that are widespread in some parts of the state, but limited or absent in other parts of the state. 
  • The goal with Class B weeds is to prevent them from spreading into new areas, and to contain or reduce their population in already infested areas. 
  • The State Weed Board designates Class B noxious weeds for control in those parts of the state where they are limited or absent, and threaten to invade other areas. Click here to view how Class B noxious weeds have been designated for control in Washington. Designations are generally based on regions. Additionally, a County Weed Board may select a Class B noxious weed, that has not been designated by the state, for greater control efforts if it is considered a local priority.
  • Landowners may be required to control Class B noxious weeds, depending on how widespread the species is and/or whether the species is a local priority. Check this list for more info on which Class B species you must control in Lewis County and review the appendix to see when and where control is mandated.

Class C Weeds

  • Class C weeds are often widespread or are of special interest to local agriculture. 
  • The State Weed Board does not require control of Class C noxious weeds. 
  • The State and many County Weed Boards generally focus on education and will provide information on identification and best management practices for these species. 
  • A County Weed Board may require landowners to control a Class C weed if it poses a threat to local agriculture or natural resources. Check this list for more info on which Class C species you must control in Lewis County and review the appendix to see when and where control is mandated. 

Quarantine Weed List

The Washington State Department of Agriculture (WSDA) maintains a plant quarantine list, called 'Plants And Seeds Whose Sales are Prohibited in Washington State'. This quarantine list consists of both terrestrial (land) and aquatic (water) plants known to be invasive and damaging. The quarantine list includes those plants whose sale or distribution is prohibited in Washington State. All Class A weeds are on the quarantine list. Some plants are entirely unknown in Washington State, but are placed on the list to prevent them from ever being imported here.

It is illegal to transport, buy, sell, or trade any quarantined species. It is also illegal to distribute seed packets, flower seed blends, or 'wildflower mixes' that include these plants. Anyone who violates the quarantine restrictions is subject to a civil penalty of up to $5,000 per violation.

You can view a gallery of quarantined weeds with information on each weed on our quarantined noxious weed list page. For more information about the WSDA Quarantine Plant List, please visit their website