New biological control will target invasive mile-a-minute weed in Michigan

Of the 119 sites confirmed in Calhoun County, most are an acre or less, but a handful of sites have 10 to 100 acres of infestation. Small sites with a few plants are hand-pulled when found, while larger sites are treated with herbicide, following guidance from Pennsylvania State University Extension, where researchers have been working to curb mile-a-minute weed infestations present since the 1930s. Both postemergent herbicides that kill the plant on contact and pre-emergence herbicide, which targets sprouting seeds, are used.

“Mile-a-minute weed is an annual vine; it has to regrow each season, so preventing the plant from producing seed and depleting the seed bank is the path to successful management," said Sara Rahn, BCK CISMA coordinator.