Many growers make no distinction at all between perennial and annual sow thistles. That’s because all three versions are tall weeds with yellow, dandelion-like flowers and stems that produce a milky sap. Seedlings of the two species(Sonchus asper & Sonchus oleraceus) are practically indistinguishable, and may be difficult to tell apart even at spray stage without examining the root system. Spiny sow thistle was covered in the previous post. Annual Sow Thistle: (Sonchus oleraceus L.) Winter annual broadleaf plant. Inhabits agricultural land and other disturbed locations. Species are not easy to… Read More →


