Weeds - Spotted Knapweed

Spotted Knapweed is a biennial or short-lived perennial. A multi-stemmed plant with several stems arising from the crown, flowers are purple or occasionally cream colored. The tips of the flower head bracts are black, thus the name "spotted."

Spotted Knapweed will form dense stands on any open ground, excluding more desirable forage species. Once established, the necessary extensive control measures are often more expensive than the potential income of the land.

Test plots by the OSU Extension Service have shown that residual chemicals are preferable when trying to control the weed. Picloram (Tordon 22K), dicamba (Banvel), 2,4-D LV and Amine are effective. Always read and follow the label. Biological controls are increasing, check with local weed control personnel for more information.