Common Name:
Japanese Knotweed
Scientific Name:
Polygonum cuspidatum Sieb. and Zucc.
Family:
Polygonaceae


Photo courtesy of
Bradley J Krieckhaus, USFS

Description: Japanese knotweed is a perennial plant that grows from creeping rhizomes. Stems grow 4 to 9 feet tall and feel woody, but die back during winter months. Greenish white or cream flowers are produced in long clusters at the ends of stems and in leaf axils. Japanese knotweed was introduced from Asia as an ornamental plant.

Control: Perennial plants require depletion of nutrient reserves in the root system, prevention of seed production and prevention of dispersal. This plant can be an attractive bush. Resist the temptation to purchase it from nursery catalogs.