Thistle – Canada

Scientific Name: Cirsium arvense

Family: Asteraceae

Structure: Up to 4 feet tall, erect.

Life Cycle: Perennial.

Leaves: Tremendous leaf variability. Varies from light to dark green, oblong or lance-shaped, deeply cut, often with spiny-toothed margins, slightly hairy below.

Flowers: Small bristly clusters, 3/8 - 5/8 inch in diameter. Light lavender to deep rose purple. Plants are male or female. Small, compact and may produce 40-80 seeds per head.

Roots: Extensive, fleshy, creeping rootstocks. Can spread up to 12 feet through the soil by root growth in a single season. Can survive up to five years underground.

Treatment:

Recommendation:
5 to 7 fluid ounces per acre of Milestone^® herbicide. Apply Milestone in the spring after all plants have fully emerged (some may be budding) until the oldest plants are in the full flower stage. Use the higher rate when applying to the flower stage. OR
2.0 to 2.5 ounces per acre of Chaparral™ herbicide OR
1.5 to 2.0 pints per acre of ForeFront^® HL herbicide OR
2.0 pints per acre of Grazon^® P+D herbicide .

Treatment-Related Literature (PDF format)
	Fall is an Excellent Time to Control Canada Thistle (166KB PDF)

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