How to Control Invasive Thistle


Q: How do I get rid of invasive thistle on my property?

A: Canada thistle (Cirsium arvense) is a perennial that grows from seed but can also be spread by roots. Elimination of thistle can take several years. A quick check will yield better results.

Thistle grows anywhere, especially in low-fertile soils and open, unlandscaped areas. Improving your soil will weaken the thistle and help the desired plants grow better. We recommend investing in a $9 soil test kit from your local extension office.

The thistle has an extensive root system. When dug up, many small roots stick out and as a result more thistles appear. Injuring and exhausting the root system by repeatedly pulling with the hand is a starting point.

Spring and fall applications of glyphosate targeting only thistle work well. To do this, put on your personal protective equipment and apply the herbicide with a 1-inch brush, thoroughly soaking the leaves and stems (at noon on a sunny, windless day for best effectiveness). Check the thistle plants weekly and reapply as needed.

Q: What plants should I consider for a pollinator-friendly backyard?

A: To support native pollinators in your garden, provide food, i.e. native plants. Milkweed, coneflowers, bees, liatris, goldenrod, asters, mountain mint, penstemon, agastache – the list goes on.

Avoid modern hybrids, especially those with double flowers. Plant several of the same perennial for masses that pollinators can easily find; vary the shape and color of the flowers. Strive for an array of blooms from early spring to late fall.

Include trees like native oaks, maples, willows, red buds, dogwoods, serviceberry, eastern white pine; and shrubs like nine thousand bark, hydrangeas, winterwood holly, aronia berries, blueberries.

Don’t forget ground covers and vines: wild ginger, Virginia creeper, golden groundsel, trumpet vine, native clematis.

To learn more about pollinators and native plants:


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