MAINE PUBLIC • October 4, 2023
Sometimes confused with bamboo, knotweed has a hollow stem and flat, shovel-shaped leaves as big as your palm. It's been in the U.S. for centuries — initially brought here as an ornamental species. But it's now considered one of the most invasive plants in the world and one of the most damaging in Maine. Japanese knotweed can grow several inches a day, is strong enough to penetrate asphalt, and can regenerate from tiny fragments no longer than your thumbnail.