A woody perennial forb, Russian Knapweed spreads by seed and rhizomes. The deep, extensive root system (up to 23 feet) makes it especially difficult to control. It emits a substance that inhibits the growth of other plants around it. The leaves, though bitter and unpalatable to livestock causes "chewing disease" (trachea paralysis) in horses.
So far Russian Knapweed has been limited to 6 counties of about 54 acres and is not currently found in Pratt County. Control methods have not been developed at this time and there are no biological controls approved for use on Russian Knapweed.
The list of approved herbicides for use on Russian Knapweed is available at your local county weed department.