About This Species
Canada thistle, despite its common name, is native to Europe and N. Asia. It spreads by its creeping roots. Plants form thick infestations that crowd out forage grasses in pastures and rangelands, reducing crop yields and production. Canada thistle is commonly found growing on roadsides, cultivated fields, pastures, logged forests, riverbanks, and other disturbed areas where it also out-grows native species. It is considered a noxious weed throughout the province.
How to Identify
It grows 0.3 to 2.0 m tall, has shiny green leaves with sharp, spiny edges and has white hairs on the leaf’s underside. It has clusters of up to five pompom-like flowers on stem tips with a faint vanilla scent. Seeds look like a dandelion i.e., parachute-type seeds. You can tell Canada thistle from all similar species by its smooth main stem and small flowers.
Report an Invasive Species
Use the app
Help us track and defeat invasive species.
Report through this website
Use our form to tell us what you’re seeing and where.
Prevention is the best approach.
Canada thistle Factsheet
If you need advice about invasive species on your property or you are concerned about reported invasives in your local area, contact your local municipality or regional invasive species organization.
Learn about best practices