Spotted knapweed has attractive pinkish-purple flowers and wooly, grey-green stems and foliage. The small florets are clustered to appear as solitary flowers at the tips of branched stems (Wilson and Randall 2003). The bracts have a black tip that gives a "spotted" appearance to the bract. Spotted knapweed grows to a maximum height of about 4 feet. From a seedling, knapweed forms a rosette with a strong taproot. The rosette can overwinter then bolt (send up flowering stalks) the following summer. In Minnesota, spotted knapweed generally blooms in July and August, although bloom time can vary depending on the situation. Individual flowers on a stalk bloom at different times to extend the overall bloom time. Spotted knapweed is a short-lived perennial plant that propagates primarily by seed. The seed can be moved by wind, water, wildlife, equipment, and vehicles. The movement of hay and gravel infested with knapweed seed allows knapweed to proliferate in new areas.