Knotweed

(Fallopia x bohemicum or F. x bohemica or Polygonum x bohemicum)

 

Quick ID:

• Grows to heights of 6-10 feet
• Stems are smooth, bamboo-like and stout
• Stems are hollow, but may be water-filled depending upon soil moisture and time of year

Habitat:

• Found in parks, gravel bars, along riverbeds, stream banks, rights-of way, and roadsides. It is also found in riparian areas and will move up watersheds.

How It Got Here:

• Originated from Asia and spread west for the last few hundred years (primarily by fragmentation)
• 10mm of plant can re-grow to maturity.
• Knotweed can propagate easily by fragmentation

Reasons for Concern:

• Can invade and thrive in a variety of habitats with no natural predators or control mechanisms.
• Itadori and Giant Knotweed have evolved into the Bohemian variety found in North America.
• Canes can sprout through 6 inches of concrete or asphalt and will damage roads & foundations to the extent they need to be replaced.