Noxious Weeds Profile - Scotch Thistle

Table of Contents

  1. Names
  2. Photos
  3. Current Status
  4. Poisonous/Cautions
  5. Growth Habit
  6. Method of Propagation
  7. Control
  8. Related Links


•English - Scotch thistle
•French - onoporde acanthe, acanthe sauvage
•Latin Name - Onopordum acanthium L.


Scotch Thistle. Scotch Thistle.

Current Status

  • Ontario Weeds Act - noxious
  • Other provinces - noxious in BC
  • Canadian Federal Seeds Act - no
  • U.S. Federal Noxious Weed - no
  • U.S. Noxious State Reg - 10 states (all western states)


  • Pub 505 - no
  • NE Weeds - no
  • Canadian Poison Plant - not listed
  • Cornell Poison Plant - not listed

Growth Habit

  • Annual

Method of Propagation

  • Seeds


  • Not listed on 2,4-D, Banvel or Roundup labels. Best time to mow is at full flowering in mid summer. Mow before seeds ripen. Mowing will not kill first year rosettes. Cultivation needs to cut them off below the rosette or crown of the plant.

Related Links

For more information:
Toll Free: 1-877-424-1300
Author: Mike Cowbrough - Chief Weed Inspector Ontario Weeds Act/OMAFRA
Creation Date: March 2003
Last Reviewed: 29 December 2006