Best way to get rid of thistles

Asked June 14, 2016, 4:24 PM EDT

Hi, Please let me know the best way to get rid of thistles. About 3 years ago, thistles started growing in my front foundation garden. I have tried pulling out the entire thistle by hand as well as using commercial weed killer. Unfortunately, the thistles have returned each year. Please see attached photos of the thistles. These thistles can grow very tall if left to do so. Thank you! Rose

Frederick County Maryland

1 Response

This is Canada thistle (not really from Canada). It is a non-native invasive plant, and very difficult to get rid of. Pulling will not dent it. Never rototill a bed of it, because each tiny piece can generate a new plant. This will take over your bed, so it is very important to address removal as soon as possible and keep at it until it is eradicated.

Here is our webpage on Canada thistle: http://extension.umd.edu/hgic/canada-thistle But sure to use the link provided there to get to control information. This is excellent advice.

If you dig this, you must get every bit of root. If you spray with a systemic herbicide containing the ingredient glyphosate, that can kill the roots, but that is also a total vegetation killer, and you must shield your desirable plants from any contact from the herbicide. Expect to spray more than once. Timing is crucial. Read the link information carefully.

ECN