Utah weeds · Perennial · peak June – August
How to get rid of Canada Thistle in Utah
How to recognize Canada Thistle (creeping thistle)
- Spiny, wavy-edged leaves along prickly stems that can reach several feet
- Clusters of small purple-pink flowers in early to late summer
- Patches of plants that all connect underground, not single plants
- Fluffy seed heads late in the season
Why it thrives in Utah
One thistle is usually a whole network. The creeping roots send up new shoots every few inches, so a single plant turns into a dense patch, especially in disturbed soil, new-build yards and neglected corners. Like bindweed, it is on Utah’s noxious weed list.
How to remove it by hand
- Wear heavy leather gloves and long sleeves. The spines go through light garden gloves.
- Pull young shoots when they are 6 to 8 inches tall, and use a hand fork to lift as much root as possible.
- Take the whole shoot every time. Cutting it off at the surface mostly makes the roots sprout again.
- Remove flower buds before they open. Once they fluff, bag the heads instead of shaking them over the bed.
- Return every one to two weeks. Repeated removal drains the roots and the patch shrinks.
When to pull it
Shoots appear in spring and flower from about June through August. The best window is before the buds open.
How to keep it from coming back
- Fill bare spots with plants or mulch so thistle seedlings have nowhere to land.
- Watch the edges of beds and the fence line, where seed blows in.
- Do not leave a neglected corner. A small patch becomes a large one in a season.
Canada Thistle FAQs
Does cutting thistle make it worse?
Cutting it once and walking away often does, because the roots send up new shoots. Cutting or pulling it again and again before it can flower is what actually weakens the plant.
How is Canada thistle different from other thistles?
Canada thistle spreads through creeping roots and forms patches, while many other thistles grow as single plants from seed. The root habit is why it is harder to clear.
Are the spines a problem when hand pulling?
Yes, which is why it takes thick gloves and some care. We wear leather gloves and work the plant from the base.
Skip the pulling
A weeder from Utah Weed Pullers can handle canada thistle for you: one visit a week, pulled by hand with no sprays, from $322 a month. We serve all of Utah County and Salt Lake County, including Lehi, Provo, Orem, Draper, Sandy, South Jordan, American Fork, Salt Lake City. See every city.