The invasive weed, called mile-a-minute weed, has been in the mid-Atlantic states, but hadn’t been found further west than Indiana, Kentucky and an outlier in Oregon.
ISU weed scientist, Bob Hartzler, the Iowa Department of Agriculture and Land Stewardship, and a field agronomist identified the plant as mile-a-minute weed (Persicaria perfoliata) after a concerned landowner in Marion County requested assistance identifying a vine that was growing around his garden.
“Although this was my first encounter with mile-a-minute weed, it was easy to see why the plant is considered a threat,” Hartzler said. “This infestation was less than a quarter acre in size, but it was crowding out existing vegetation. The weight of the plant was pulling down a stand of miscanthus, a species known for establishing monocultures.”
It’s currently unknown how widespread mile-a-minute weed is across the state.
The infestation found was estimated to have been present for at least five years.
Mile-a-minute weed is a herbaceous annual vine that can grow up to 20 feet in length. Its leaves are triangular and light green. The stem has many sharp, downward curving spines. It also has round, iridescent blue fruit about 0.25 inches in diameter from mid-July until frost.
It grows best in sunny, moist locations with an abundance of leaves, duff, or brush on the soil. Seeds can spread by water, rodents, birds and humans.
Anyone who thinks they may have an infestation can contact Bob Hartzler at 515-294-1164 or [email protected], or contact deputy weed commissioner for the Iowa Department of Agriculture and Land Stewardship Lane Kozel at 515-725-1468 or [email protected]
While there is no easy way to get rid of the invasive species, Iowa officials are investigating the use of a weevil that is host-specific to the invasive vine.