Noxious Weed Lists

The Washington State Noxious Weed Control Board manages noxious weeds. The board advises the Washington State Department of Agriculture about noxious weed control in Washington State. In addition, it serves as the state’s noxious weed coordination center. Through actions and policy decisions, the board coordinates and supports 48 county noxious weed control boards and Washington weed districts.

Each year, the State Noxious Weed Control Board adopts, by rule (Washington Administrative Code 16-750), the state noxious weed list. This list determines which plants the board will consider noxious weeds and where control will be required in Washington State. This approach supports landowners’ efforts to protect and enhance Washington’s agriculture and natural areas in the most cost-effective manner.

Class A Weeds

Non-native species that are limited in distribution in Washington. State law requires that these weeds be eradicated. To see images of Class A noxious weeds, please visit the board’s Class A Noxious Weeds page.

Class B Weeds

Non-native species that are either absent from or limited in distribution in some portions of the state but very abundant in other areas. The goals are to contain the plants where they already are widespread and prevent their spread into new areas. To see images of class B noxious weeds, please visit the board’s Class B Noxious Weeds page.

Class C Weeds

Non-native plants that already are widespread in Washington State. Counties may choose to enforce control, or they can educate residents about controlling these noxious weeds. To see images of Class C noxious weeds, please visit the board’s Class C Noxious Weeds page.

Monitor list

Putting plants on the Monitor List allows the state to gather more information about noxious weeds, such as their distribution, observable impacts, spread rate, and more. To learn how to participate in the listing process visit the the board’s listing process for noxious weeds page.

Prohibited Sales of Plants and Seeds

The Washington State Department of Agriculture’s list of prohibited sales of plants and seeds identifies plants known to be invasive and a detriment to the state’s natural resources. These regulations serve to prevent the introduction of these problem plants into Washington. State law prohibits transporting, buying, selling, offering for sale, transplanting, or distributing plants or plant parts of these regulated plants, into or within Washington.

Prohibited and Regulated Species List

The Washington State Fish and Wildlife Commission considers these species to have a high risk of becoming an invasive species. These species may not be possessed, imported, purchased, sold, propagated, transported, or released into state waters, except for transporting to the department or its designee for the purposes of identifying or reporting the species. The unlawful release of a prohibited aquatic animal species is a gross misdemeanor. A second violation within 5 years is a Class C felony.

Regulated aquatic animal species 
The commission considers these species to have a moderate, but manageable, risk of becoming an invasive species. It prohibits their release into state waters. These species include commercial aquaculture species and species listed by the commission as food fish or game fish.

Previous Priorities

The council previously included the invasive species below in its top 50 priorities list. Although they still are potential threats to Washington, the council has made great progress in preventing their introduction or spread and has updated the list to reflect the most pressing concerns.