Tundra performed very well for us on both grassy and broadleaf weeds including sow thistle. Perennial sow thistle is very palatable and is will be selected by cattle if they are exposed to the plant at the correct time of the year. Sow thistle. Rights . The item The control of Canada thistle and sow thistle in Alberta, by G. R. Sterling. Trouver la feuilles de chardon photo idéale Une vaste collection, un choix incroyable, plus de 100 millions d’images LD et DG abordables de haute qualité. In Alberta this weed first evolved resistance to Group B/2 herbicides in 1996 and infests Pastures, and Spring Barley. Alberta. Perennial Sow Thistle is a perennial that is commonly confused with Annual Sow-Thistle and Prickly Lettuce. Take a minimum of 20 weed counts across the field. Geographic coverage. Common Name: Sow thistle, Annual : Family Name: Sunflower: Latin Name: Sonchus oleraceus: Provincial Designation: Common : Life Cycle: Annual: Mode of Spread: Seed: Pest Comments <