Town of
Nassau
Japanese Knotweed

Japanese Knotweed
Japanese Knotweed

Japanese Knotweed

Japanese Knotweed (common names fleeceflower, Mexican bamboo, huzhang)

 

Japanese Knotweed, scientific name Fallopia japonica, was introduced to the United States from Asia as an ornamental plant in the late 1800s.

 

The plant is very successful in the US and other countries, and is considered one of the world’s worst invasive species.

 

Japanese Knotweed is a strong grower and can damage manmade structures such as building foundations and roads, and can create a flood hazard by blocking drainage ditch flow.  It grows densely and crowds out other herbaceous species.  Its root structure, or rhizomes, can survive a wide range of temperatures, and because of their depth, make removal by excavation very difficult.  It re-sprouts from the root system so cutting does not control the plant. Applying herbicides is the most effective method of control, at a time in late summer or fall when the plant is close to flowering.  Researchers are also exploring biological pest control using the jumping plant louse Aphalara itadori and a leaf spot fungus from genus Mycosphaerella.