Nodding thistle (Carduus nutans)

Nodding thistle

Carduus nutans


  • Solitary flowers at the end of a 20 cm – 2.5 m tall stem
  • Alternate leaves, waxy cuticle
  • Flowers are purple-red with spiny bracts surrounding the flower.
  • Called ‘nodding thistle’ because the flowers droop down as they mature.

Introduction and spread

  • Native to Europe
  • A nodding thistle plant may produce up to 20,000 seeds
  • Seeds can be transported to new areas via vehicles, equipment, or clothing
  • Prefers to establish on disturbed sites.

Consequences of invasion

  • A problem in grasslands where grazing animals favor grasses over the thistle, giving it a growth advantage
  • Outcompetes native grasses
  • Creates impenetrable thickets

Status in the CKISS region

  • It has only been found in the Lower Arrow Invasive Plant Management Area of our region.
  • Measures are being taken to eradicate this species where it is found, and to prevent further spread into new sites.
  • Please report any findings of this species immediately.
  • To learn more about how CKISS classifies and manages invasive species, see our Invasive Species Priority Lists page.

Integrated pest management options


  • Be PlantWise! Choose only non-invasive plants for your garden.
  • Learn to properly identify nodding thistle
  • Clean equipment and gear before leaving an infested site


  • Hand digging and mowing can be effective if repeated over a period of time
  • Mow just before plants flower to reduce seed production.
  • Transport securely and dispose of removed invasive species properly at a landfill

Additional resources