Time to Start Planning Canada Thistle Control
Friday, June 10, 2022
Canada Thistle is a creeping perennial that is found in all parts of the County. This noxious weed is a prolific seed producer, producing an average of 5,000 viable seeds per plant and can be viable in the soil for up to 6 years. Plants produce both a taproot that can go as far as 8 feet deep and a fibrous root system.
Mowing, pulling, or using a registered broadleaf herbicide are all considered control measures that can be conducted throughout the whole growing season. Studies show the most effective control option is a herbicide application that translocates. Applying in the spring during the rosette, pre-bud stage or in the fall when plants are taking in nutrients to overwinter are the best options to ensure translocation however an application mid summer may be necessary to prevent plants from going to seed.
More information on Canada Thistle and other weeds of concern in Rocky View County can be found here. Also, a useful invasive weed ID booklet can be found here and specific weed fact sheets can be found on the Alberta Invasive Species Council website.
Weeds & Pests