I attach 3 pictures of a weed that has utterly defeated me. It is like a...

Asked September 17, 2017, 5:20 PM EDT

I attach 3 pictures of a weed that has utterly defeated me. It is like a vine, spreading by underground runners. It grows in the center of thick periwinkle and pachysandra (sp) beds. Pulling it out of the ground does not help as the roots remain. Poisons like Ground Clear do not work. It is a perennial and I do not know its name. How can I kill it?

Thank you

Howard County Maryland

1 Response

It looks like you might be dealing with Canada thistle. Do the plants feel prickly to the touch? Take a look at the photos on this website and see if they resemble what you have (https://www.marylandbiodiversity.com/viewSpecies.php?species=4237).

Canada thistle is a difficult invasive weed. https://extension.umd.edu/hgic/canada-thistle It is a perennial, so it will continue to return from the roots if all of it isn't removed. Remove stems before they produce flowers and set seeds. Hand-cut or mow the stems repeatedly, which will eventually exhaust the root system. Cut or mow the stems all the way down to the ground at the appearance of new growth. For chemical treatment, you may need to spot-treat the individual plants repeatedly with glyphosate. This chemical moves within the plant down into the roots to kill them. It takes a lot of effort and persistence to control this plant.

The following video has more information about Canada thistle and what you can do.
https://www.youtube.com/watch?v=qoONBIB0S3o&index=1&list=PL942C7AED5F1D72A7

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