Answer: Along with bindweed, quackgrass, and nutsedge, thistle is one of the champion persistent weeds. Chemical controls aren't always effective (or safe). Deep-rooted weeding takes care of some but not others and it never gets the seeds which produce more. Try chopping down or digging out those that you can and put down a black plastic mulching material such as our Miracle Mulch IRT on page 139 of our catalog.
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