- broadleaf weed with spiny oblong leaves and tufted purple flowers
- stems can be up to 1 – 4 feet tall, however it will continue to grow if mowed or cut
- landscape, lawn and open spaces
- perennial with extensive underground roots
- flowering occurs June through August
- Hand-pull plants in planting beds prior to seed maturation; use caution when digging out plants since underground roots that are missed can quickly regrow.
- Apply a mulch layer 3 inches deep on planting beds to reduce seed germination.
- If Canada thistle becomes established, post-emergent herbicides are effective, particularly with several repeat applications.