Yellow hawkweed identification and control
Legal status in King County, Washington
Yellow hawkweed, on the state list since before 1988, is a Class B Noxious Weed in Washington in the group of hawkweeds known as meadow hawkweeds (in the subgenus Pilosella). Meadow hawkweeds are designated for required control in King County by the Washington State Noxious Weed Control Board and as a group are on the list of of Regulated Class B Noxious Weeds in King County. Public and private landowners are required to control infestations of yellow hawkweed on their property in King County.
Yellow hawkweed is also on the Washington quarantine list (known as the prohibited plants list) 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.
For more information on noxious weed regulations and definitions, see Noxious weed lists and laws.
Identification and biology
The leaves are long and narrow, up to six inches long, not lobed, somewhat hairy on both sides, and form a basal rosette. There are also usually one or two small leaves on the stem. The entire plant contains a milky juice. Yellow hawkweed has a shallow root system and underground creeping stems called rhizomes. New plants can arise from buds on the rhizomes and plants can develop several creeping stems (like strawberries) that are also capable of producing new plants.
Hawkweed identification can be difficult and often requires technical details such as hair types. Also, hybridization between species can make it even more confusing. For a positive identification, you should consult a technical flora on hawkweeds or contact the noxious weed program.
Additional information on yellow hawkweed (meadow hawkweed)
- Hawkweed weed alert (1.76 MB Acrobat file)
- Hawkweed Best Management Practices (82 KB Acrobat file)
- University of Washington Burke Museum Herbarium (external link)
- Washington State Noxious Weed Control Board (external link)
- Idaho Weed Awareness meadow hawkweed information (external link)
- Invasive and exotic species meadow hawkweed information (external link)
What to do if you find this plant in King County, Washington
Please notify us if you see yellow hawkweed 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 yellow hawkweed 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 yellow hawkweed in order to help us and others locate new infestations in time to control them.
Yellow hawkweed photos
Report yellow hawkweed in King County, Washington
- Please notify us through our online infestation form
Locate yellow hawkweed in King County, Washington
- Use our interactive noxious weed map and search for yellow hawkweed