“Herbaceous perennials, such as quackgrass, mugwort, and Canada thistle, die back to the ground each year.”
“These may be the best teeth for hard or rocky soil and for heavy infestations of quackgrass and other weeds with underground rhizomes.”
“Perennial grasses such as bluegrass and quackgrass and broadleaves such as Canada thistle, bindweed, and curly dock also could be addressed with the weed control program.”