Bull thistle (Cirsium vulgare)
 Native Substitutes:
 Control Methods  
Mechanical
 Chemical
 Biological
Pulling or mowing in early bud or bloom stage, then dispose off site Spot-spraying with glyphosate or triclopyr when plants are in rosette stage (first year) in the fall when non-target plants are less susceptible

Thistlehead-feeding weevil and rosette-feeding weevil

Caution: Weevils have been observed feeding on native thistles

    Do not use in high quality natural areas    
 
Appearance: Bull thistle is a biennial forb, between 3-6' tall with one erect branched stem. A rosette grows in its first year and the plant blooms in its second year. Leaves: Alternate, coarsely lobed, each lobe with a spine at its tip. Spines extend downward from the leaves along prominent ridges of the stem. Upper leaf surface is rough. Flower: Disk-shaped flowerheads contain hundreds of tiny individual purple flowers which bloom from June to August. Seed: Reproduction only occurs through up to 10,000 straw-colored seeds with plume-like bristles. Seeds remain viable in the soil for over 10 years. Root: Each plant has a fleshy taproot.

Bull thistle colonizes primarily in disturbed areas such as pastures, roadsides, and ditch banks, but also in hayfields and disturbed prairies. It is unpalatable to most grazing animals and therefore invites selective grazing, giving the thistle a competitive edge. It generally does not pose a threat to high quality areas. Does not withstand cultivation. Introduced to the U.S. in the early 1800s from Europe and Asia and is declared a rangeland pest.

Legal Status: This plant is a prohibited noxious weed in Minnesota and must be controlled or eradicated as required by Minnesota Statutes, section 18.78.

Wisconsin Manual of Control Recommendations for Ecologically Invasive Plants, 1997.
Plant Conservation Alliance: Alien Plant Working Group www.nps.gov/plants/alien/fact
The Nature Conservancy Element Stewardship Abstract