This Class B noxious weed has a limited distribution in King County, and control is required. This species is also on the Washington quarantine list (known as the prohibited plants list) (external link) and it is prohibited to transport, buy, sell, offer for sale, or to distribute plants or plant parts, seeds in packets, blends or "wildflower mixes" of this species, into or within the state of Washington.
In western Washington this weed is sometimes found on roadsides or along railroad tracks in very dry, disturbed sites. In eastern Washington, kochia is widespread, and many counties report thousands of acres.
Introduced as a garden ornamental from Asia in the early 1900's, this weedy annual spread state by state. It reached eastern Washington by 1980. Kochia is very drought tolerant and can invade both irrigated and dryland crops. The economic impacts hit crops such as potatoes, alfalfa and wheat.
Additional information on kochia
What to do if you find this plant in King County, Washington
Please notify us if you see kochia growing in King County. Our program staff can provide the property owner or appropriate public agency with site-specific advice on how best to remove it. Also, because kochia is not established in King County, we have an opportunity to stop it from spreading if we act quickly. We map all known locations of regulated noxious weeds such as kochia in order to help us and others locate new infestations in time to control them.