The fast-growing Persicaria perfoliata — also known as mile-a-minute vine, mile-a-minute weed, devil's tearthumb, and Asiatic tearthumb — can grow up to 6 inches/day. It first appeared in Greenwich in 2000 and has since spread into 15 Connecticut towns, smothering other native plants along the way. It is also creeping north into Massachusetts. Visit www.hort.uconn.edu/mam.