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Perennial sowthistle identification and control: Sonchus arvensis

Perennial sowthistle identification and control

Sonchus arvensis


Perennial sowthistle, a Class C noxious weed, is an herbaceous perennial that grows 1.5-6 feet tall in farms, meadows, forests, disturbed areas, and a variety of other settings. It has hollow stems containing a milky juice, alternate leaves with spiny edges, and bright yellow, 1.5-inch-wide flower heads. This weed reproduces via seeds and rhizomes.

Additional information on perennial sowthistle

What to do if you find this plant in King County, Washington

If you wish to control perennial sowthistle, our program staff can provide site-specific advice on how best to remove it. The county isn't currently tracking locations of this species.

Report perennial sowthistle in King County, Washington

Locate perennial sowthistle in King County, Washington

Related information

Related agencies

Program offices are located at 201 S. Jackson St., Suite 600, Seattle, WA 98104. To contact staff, see the Noxious Weed Control Program Directory, send an email, or call 206-477-WEED (206-477-9333).