Be on the Lookout for Mile-a Minute Vine!

posted 9/24/14, updated 10/27/22

Mile-a-Minute Vine (Persicaria perfoliata formerly Polygonum perfoliatum), an invasive Asian annual weed accidentally introduced into Pennsylvania, has been moving steadily northward. Until recently, the northern front of the invasion was southern New York State and southwestern Connecticut. In 2004 and 2005, two populations were discovered in New Milford and Bridgewater, CT, and, in 2007 two large populations were discovered in Newtown, CT. Since then MAM has been discovered in many parts of Connecticut. See for the current map.

MAM is a serious threat to agriculture, the economy, and the environment. It smothers fields, shrublands, and forest edges. The vines can grow six inches a day and can climb more than 20 feet high, blanketing everything in sight.

photo by Katrina Schindledecker

MAM seeds are spread by birds, other animals, soil and water. The populations in Newtown probably originated from seeds in soils brought in for landscaping. Water carrying seeds downstream can spread the populations with a terrifying speed. A Newtown town official walked the Pootatuck River corridor in 2004 and did not see any MAM plants. In 2007 MAM was found extending a mile or more down the river corridor, covering several acres of floodplain.

MAM plants grow almost anywhere except lawn, very dark forests, and in water. They are often found growing with other invasive plants, especially multiflora rose. Seeds germinate in early April. Plants grow slowly at first, then, depending on the growing conditions, begin producing seeds sometime between late June and mid-August. Some seeds don't germinate the first year - areas where Mile-a-Minute Vine has been found will need to be monitored for many years.

Mile-a-Minute Vine is very easy to recognize. The leaves are equilateral triangles. There are tiny barbs on the stems. The plants have weak stems that clamber over trees and shrubs. The vines don't twine - they just grow upwards, sticking to things with the tiny velcro-like barbs.