Noxious Weeds Profile - Scotch Thistle

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

Names

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

Photos

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)

Poisonous/Cautions

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

Growth Habit

• Annual

Method of Propagation

• Seeds

Control

• 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.

• Ontario Weed Gallery: Scotch Thistle
• Ontario Vegetation Management Association