May 27, 2017
Property gossip August 2016

Trying to secure finance on a property where Japanese knotweed is growing in the garden can be extremely problematic. If Japanese Knotweed is growing on land adjacent to the property being financed, this too can pose a problem. But what do you know about this herbaceous perennial plant?

If you have a garden, here are a few things you ought to know about this invasive plant.


It can be very difficult to spot Japanese Knotweed and can often be mistaken for Bamboo, Broadleaf dock, Bindweed, Russian vine or Ground elder. In the spring, reddish/purple shoots appear, growing up to 2cm’s per day. Bamboo-like stems spread from the roots and will produce heart-shaped/shield-shaped green leaves, which come late summer/autumn will develop small creamy white flowers. If you suspect you have Japanese Knotweed, then it’s best to speak to an expert.

Is it a big problem?

In a word “yes”, if left to its own devices. The plant can grow 3 metres high with the underground rhizome system extending laterally by 2-3 metres and up to 3 meters in depth.

Japanese Knotweed can damage property, finding its way through any weakness such as expansion joints in the concrete, cavity walls and broken mortar. Drains and sewers are also at risk of being damaged, and in extreme cases, structural damage can occur.

What to do if you “think you have” Japanese Knotweed
Firstly, you need to speak with a Japanese Knotweed eradication expert, who may be able to provide an estimate from photos, or they may need to arrange a site survey.

If verified, there are a number of treatments available, split into two broad categories: herbicide treatment or physical removal. Do not cut corners by chopping away at the plant, which will likely result in you spreading the plant to other parts of your garden, and someone else’s for that matter.

Will the plant come back after treatment?
Possibly, there could be some minor regrowth after herbicide treatment, but this should be covered by the treatment plan and be dealt with accordingly.

A few facts

The plant originated from Eastern Asia and was introduced to Britain as an ornamental plant in the mid-nineteenth century.

Japanese Knotweed is classed as “controlled waste” under the Environmental Protection Act 1990. As such you should never try and dispose of the plant in your normal household waste/garden or green waste collections.

It is not illegal to have Japanese Knotweed in your garden, but you risk the chance of the plant spreading to neighbouring land and causing damage to someone else’s property (as well as your own of course)

It is an offence to plant or cause Japanese Knotweed to grow in the wild.