Appearance: Biennial or short-lived perennial herbaceous plant, 2 - 3' high. Basal leaves form a rosette the first year from which grow 1- 20 wiry, hoary, branched stems during the second year.
Leaves: Alternate, grayish, hoary, and divided into lance-shaped lobes decreasing in size at the top.
Flowers: Thistle-like pink to purple flowers sit at the tips of terminal and axillary stems, bloom from July through September.
Seeds: Brownish, 1/4" long with small tuft of bristles, dispersed by rodents, livestock and commercial hay. Seed viable in the soil for 7 years.
Roots: Stout taproot. Lateral shoots form new rosettes near the parent plant.
Caution: Wear long sleeves and gloves, can be a skin irritant to some people.
Early detection and pulling
Mowing as needed so plants cannot go to seed
Prescribed burning, only very hot burns are effective which may also damage native plants
Apply selective herbicide clopyralid during bud growth in early June for best results (48 oz per 100 gal water). Use caution in quality natural areas herbicide affects native plants of the sunflower and pea family as well.
BiologicalSeedhead weevils, root-boring weevils, and seedhead flies are commonly used