The Problem with Japanese Knotweed

Part of our Japanese Knotweed Removal Guide. Click to see more answers to your questions.

After the Victorians bought Japanese Knotweed over from Japan (surprisingly enough) during the 19th century and quickly realised they were unable to control its growth, their lax outlook on the environmental impact of letting the plant grow out of control has left us with a serious problem.

The rapid growth and spread of the plant has earned it the title of the most invasive plant in the UK. With no natural enemies it’s down to us to deal with it and at an estimated cost of £1.3 billion to eradicate the problem it will not be a quick or cheap process. The stems dominate areas, crowding out indigenous species and have the potential to alter the ecosystem, destabilise riverbanks and damage foundations. The dead stems represent a haven for vermin, seem to gather litter and look particularly unsightly.

It has been reported that knotweed has the potential to grow through concrete, brick and tarmac. This won’t happen unless there are pre-existing cracks/gaps for the plant to exploit and worsen. The speed of growth can widen a small crack noticeably in a short period of time making it look like the plant caused the crack in the first place leading to this reputation. This had led to some mortgage companies not lending on properties with Knotweed present.