This non-native plant is extremely invasive and difficult to eradicate. At one time, the Ham Lands were severely affected by many large, dense stands of it. The Council mounted a major eradication programmed in the 1990s. Thankfully, this highly expensive venture was a great success. However, a few small clumps have now reestablished and will need specialist treatment. The law says - you must not cause Japanese knotweed to grow in the wild. Not only will Japanese knotweed spread by its highly vigorous root system, but it can regenerate from stem fragments. Fortunately, only one clone of female plants was introduced in the UK, so distribution by seed does not occur. Hybrids with other species have been recorded but are infrequent.

If you do see any Japanese knotweed plants please do not try to remove them or break bits off; instead please report the occurrence to us so that it can be professionally eradicated.

Please look at the individual picture for more information how to recognize the knotweed.

To contact us please email

Stems - These are cane-like and often reach 2m tall. They are usually speckled with red, rather like rhubarb sticks. The younger stems and side branches typically have a zigzag shape, with one leaf attached at each angle. The dead canes remain standing throughout the winter.



Leaf- These are mid green and triangular to heart-shaped, c 12x10 cm. The tip is pointed and the base straight across (not curved up where the leaf-stalk is attached).


Flowers - creamish-white catkin-like clusters or spikes of small female flowers occur in August.