Bull Thistle

bull thistle habit
bull thistle flower

Bull Thistle

Cirsium vulgare

Information Sheet (PDF)


List B - Eradication Required


General

  • Family: Sunflower (Asteraceae)
  • Introduced from Europe


Habitat

  • Biennial forb
  • Found in drainages, meadows, rights-of way, disturbed sites


Plant


Vegetation

  • ½ inch wide and 2-4 inches long
  • Leaves alternate
  • Leaves on older plants clasp the stem and are divided into segments
  • Plants up to 3 feet tall
  • Prickly on top with cottony hairs on the underside


Roots

  • Taproot


Flower

  • 1½ - 2 inches wide
  • Bracts covered with spines
  • Color: purple
  • Season: June to August
  • Single


Seed

  • Up to 4,000


Reproduction

  • Seed


Control


Biological

  • None


Chemical


Cultural

  • Prevention
  • Removal - make sure the entire root is removed. Must be repeated as new plants germinate


Mechanical

  • Burning - N/A
  • Grazing - N/A
  • Mowing - Prior to seed set.  Mow every three to four weeks. Works best when combined with fall herbicide treatments


Use all chemicals according to the manufacturer's label. No specific recommendation or endorsement is made or implied by listing methods or products.