Biennial, large purple flower, flowering in early June. Flower heads are solitary and usually nodding. Height 3 to 6 feet.
An aggressive plant spreads rapidly to form dense stand, often displacing desirable forages and grasses. Found in pasture, range and timber lands.
Easy to control in first year of growth (seedling, rosette stage). Fall or early spring applications can be made. Several selective herbicides are available. Call your local weed control supervisor, or chemical consultant for specific recommendations.
Seedhead weevils are widely established, and may be beneficial on large acreage sites.