Originating from the volcanic regions of Japan, Japanese Knotweed thrives on disturbance and has used this attribute to spread down watercourses, along transport routes and on to waste land.
The plant itself is a perennial, it will re-establish itself year after year and spreads via an extensive underground rhizome (root) system. This can grow underground for up to 7 metres laterally and 3 metres in depth according to Environment Agency guidelines. It then uses this root system to grow up in other places.
In its native region Japanese Knotweed is controlled by a range of natural pests and diseases including a weevil and rust fungus. Here in the UK, without these restrictions, it is thriving and its vigorous growth is a problem to our wildlife and capable of damaging buildings and hard surfaces. Once it is established in the built environment it can be particularly difficult to control.