Japanese knotweed is a tall (2-3m) plant with bamboo like stems. It has large, shield-shaped leaves and creamy white clusters of flowers from June to September. It often develops into dense thickets. It is a perennial plant so, although it dies back over winter, it regrows from the base in the spring. It doesn’t produce seed in the UK but spreads through rhizomes (underground stems) or parts of cut stems.
Japanese knotweed (Fallopia japonica) is an invasive plant that can cause damage to property, and is very difficult to control once established.