Illinois Extension Educator Richard Hentschel discusses weeds in the landscape, perennial and vegetable beds. While dandelion and plantains and other broadleaved weeds are well known, a new comer showing up more often are the thistles. Canadian thistle is particularly troublesome by the way the underground roots easily spread the weed around the beds. To slow the populations down, cultivate very shallowly, water the plants and not the whole bed and get those weed out while they are early.