Yellow Star Thistle

Life Cycle

  • Annual

Growth Habit

  • Erect, up to 5-feet tall

Plant Emergence

  • Seedlings in early spring
  • Flowers late May / June until frost


  • Deeply tap-rooted; reproduces by seed
  • Stiff, wiry, winged stems
  • 3/4" yellow flowers covered with spines
  • Toxic to horses; causes "chewing disease"


  • Grazing, mowing, burning, pulling, digging can be effective prior to seed production
  • Apply Milestone; 2,4-D; Curtail; Banvel; or Tordon to actively growing plants before flowering