Japanese knotweed giving you fits? Here’s how you can kill it

PORTLAND PRESS HERALD • July 10, 2026

apanese knotweed is among the world’s most invasive, resilient plant species. In Maine, it has spread “everywhere,” said Abigail Edenfield, Presumpscot Regional Land Trust’s environmental steward from Maine Conservation Corps. Travelers brought the plant from eastern Asia to North America in the late 19th century to adorn domestic gardens. The species is highly damaging to Maine’s natural ecosystems. Enter Mainers, who are working to remove the unwelcome plants not only from their own gardens and yards, but also from their communities more broadly.