how to safely remove invasive thistle plants

Asked June 3, 2019, 11:31 AM EDT

We had an old garden patch on our property and it became completely overtaken with thistle and its slowly trying to regenerate itself in the grass around the old garden patch and its been growing for 3 years on the patch but only these last 2 years has it tried to get into the grass areas around it. This plant took route when unfortunately Enbridge Line 5 installed its new pipeline which crossed our property and at that time we found out that our property was designated as a federally protected wetland so we would like to protect it as much as possible. I believe Enbridge workers probably disturbed the area and the seeds from this thistle was redistributed to the fertile ground of the old garden patch. I believe my neighbor who wanted to help me out but knew how I did not want to use a chemical may have used a herbicide on it last fall but I am trying to do my part to save our planet and I want to do it as safely and responsibly as possible without using anything Monsanto and to do it eco friendly. I am at a loss of how to get rid of it. Do I pull it out, but then what do do with it? Do I burn it, but will it release more seed that way. I truly need some guidance. Thank you in advance.

St. Clair County Michigan

1 Response


There are mechanical techniques to manage thistle and, over several seasons, you will minimize it. Scout and cut to the ground multiple times per growing season, do not let seed set(clip flower heads off, at least, and discard), and tilling areas like old veggie gardens, to expose the roots in late fall over winter, are some of these mechanical techniques. Unripe seed or flower heads will not sprout new plants. Roots can be dried and burned or sealed in bags and thrown away.

Here is an organic reference- see “Mechanical Control of Canada Thistle”

And another write up on organic methods, including smothering-

Small plants can be dug up effectively, so keep after those with a heavy glove and trowel. Bagging all plant parts and sealing the bag, or drying the plants thoroughly in the sun and then discarding, is safe to do as long as no ripe seed is present. Any seed can be sealed in a bag or container and discarded.

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