Annual Sow Thistle

Annual Sow Thistle is also known as:
  • Common Sow Thistle
  • Spiny Milk Thistle
  • Spiny-Leaved Sow Thistle
  • Cultivated fields
  • Gardens
  • Riverbanks
  • Roadsides
The annual sow thistle measures between 0.1 and 1.0 meters. They have a single stem branching out near the top. Stems are hallow and exude a milky juice. The flowers are small, yellow dandelion-like flower heads. Leaves are deeply lobed and basal leaves end with a large pointed segment. Seeds are 2.5 - 3.5 mm long, reddish brown and ribbed. They also have a very short tap root.

Control Practices
  • Chemical control is an option
  • Cultivation
  • Intensive grazing by cattle and sheep can prevent seed-set
  • Mowing lower than 20 cm before they go to seed can prevent regrowth