Thistles in Garden

Q: The last two years I have been getting more and more thistles in my garden. I've tried to kill them with bleach and lawn killer....any suggestions how to get rid of them?

Bridget in Euclid

A: I would try a product containing the herbicide glyphosate and follow the label directions carefully.

When applying an herbicide, be careful not to get it on other, desired plants as the herbicide cannot tell which plant you want to kill and which plant you don't. To protect neighboring plants, you can shield them with a piece of cardboard held between them and the thistle plant(s).

If you are averse to using chemicals, you can pour boiling water on the thistle's root system (I've found this to be a very effective way to discourage ants from nesting in between our patio stones).

As long as the boiling water doesn't come in contact with the root systems of desired plants, this can be an effective method. You would need to repeat this as often as needed until you've gotten rid of the thistle.