Japanese Knotweed and development

Japanese Knotweed has become infamous for the problems it causes in the urban environment.  In particular building development has been hampered by this aggressive weed.

Introduced in the early 19th century as a garden plant, Japanese Knotweed was starting to be highlighted as a pest by the beginning of the 20th century.  Now widespread across the whole of Britain, it is rarely absent from the urban environment.

Where the plant grows on development sites it can cause potential risks such as damaging hard structures and surfaces.  Developers are also often required to tackle it in order to maintain their legal obligations under the Wildlife and Countryside Act 1981. 

There are no definitive industry wide figures for how much Japanese Knotweed costs, but even on relatively small sites the cost of control can run into hundreds of thousands of pounds and the annual cost across Britain is likely to be many tens of millions.  The cost to eradicate it in Britain using conventional methods was estimated to be £1.56 billion.

Japanese knotweed growing through concrete

Japanese knotweed overgrowing a garden border

Thin strip of image show tree trunk and bark