Fall is a good time to control biennial and perennial pasture weeds, reminds Jane Hanson, Dow AgroSciences range and pasture specialist.

She says fall rain and cool temperatures bring on a flush of regrowth and germination of biennials such as musk and plumeless thistles. These lush plants and new seedlings are very susceptible to herbicide treatments. Plus, if you use a product with residual control, you'll continue to get activity through early spring.

“Keep weed seedlings at bay during this critical time and you'll give pastures a head start on the growing season,” says Hanson. “This also can help develop a thick grass cover that can work to prevent future weed infestations.”

Deep-rooted perennial weeds like Canada thistle, sericea lespedeza and leafy spurge are susceptible to fall treatments for another reason. Perennials move nutrients into their root systems as winter approaches, and fall-applied herbicides travel with them, resulting in excellent control, says Hanson.