Washington's Noxious Weed Laws

Why we have weed laws

Weed laws establish all property owners’ responsibility for helping to prevent and control the spread of noxious weeds. Since plants grow without regard to property lines or political jurisdictions, everyone’s cooperation is needed – city gardeners, farmers, government land agencies, foresters, and ranchers all have a role to play.

Washington’s weed laws spell out these responsibilities, and create the government infrastructure needed to educate citizens and ensure that the laws are respected.

Washington’s weed laws also direct the state Noxious Weed Control Board to create and maintain the state’s official list of noxious weeds that landowners may be required to control.

Washington is a national leader in weed law

Washington’s first weed law was passed in 1881 to fight the spread of Canada thistle, a weed that was accidentally brought by early settlers.

In the late 1960s, the state legislature established the state’s Noxious Weed Control Board, and authorized counties to establish County Weed Boards. Thirty-eight of Washington’s 39 counties have such boards. There are also a handful of Weed Districts that are contiguous with Irrigation Districts.


The Laws

RCW 17.10, (Revised Code of Washington) is the state’s basic weed law.

The Washington Administrative Code (WAC) contains the rules and regulations needed to carry out the state law.

WAC Chapter 16-750 includes the state Noxious Weed List, definitions and descriptions of region boundaries for Class B weeds, and the schedule of monetary penalties.

WAC Chapter 16-752 describes the quarantine list maintained by the state Department of Agriculture. (The state law that calls for the creation and maintenance of the quarantine list is RCW 17.24.)

Clipart of green legal scales.

How the state weed list is organized into three classes of weeds

The state’s weed list is organized into three categories: Class A, B, and C.

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.)   Class A List

Class B weeds are those that are widespread in some parts of the state, but rare 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. Your local County Weed Board can tell you which Class B weeds are designated for control in your area.   Class B List

Class C weeds are typically common and widespread. Rather than requiring control of these plants, most County Weed Boards simply offer advice to landowners about the most effective control methods. A County Weed Board may, however, require landowners to control a Class C weed if it poses a threat to agriculture or natural resources.   Class C List

The quarantine list: plants whose sale or distribution is prohibited

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. All Class A weeds are on the quarantine list. Some plants are placed on the list to prevent them from ever being imported to our state.   Quarantine list

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.

What it means to 'control' weeds

Controlling weeds means not letting weeds reproduce. Usually, that means not letting them go to seed. Legally, control means to prevent the dispersal of all propagating parts capable of forming a new plant.

Penalties for landowners who fail to control noxious weeds

County Weed Boards and local Weed Districts may come and control the weeds (by spraying or pulling them) and bill the landowner. If the landowner doesn’t pay, the cost becomes a lien on his or her property.