Bull Thistle displaces native vegetation and can form dense thickets. Bull thistle is a Class "C" Noxious Weed in Benton County and it is the landowner's responsibility to control (RCW 17.10).
Tilling, mowing twice a season, or cutting the plants below the soil surface can be effective control for bull thistle. There are several herbicides that are effective on bull thistle. Please follow the label for all herbicide use. Contact the Benton County Noxious Weed Control Board by phone: (509) 943-6005 or by e-mail: email@example.com if you have any questions.