Canada thistle forms extremely extensive root systems that need to be repeatedly damaged to keep them from growing back. These root systems can spread very aggressively and can expand from 6 feet wide ...

“New plants pop up from the roots, so where you had one Canada thistle last year, you might have 30 this year, and they are ...

European marsh thistle, a terrestrial and wetland herbaceous biennial in the Asteraceae family, is an invasive plant that prefers moist soils ... European marsh thistle is distinguished from Canada ...