Japanese Knotweed was brought into the UK from Japan in the Victorian era. In Japan, native predators effectively controlled the spread of this plant. However, this is not the case in the UK. 

Japanese Knotweed spreads very quickly and aggressively. It can cause serious structural damage to buildings in that it’s roots can extend up to 3 metres in depth and 7 metres in all directions. These roots can then have a devastating impact to buildings foundations and drains. 

Whilst it is not illegal to have Japanese Knotweed in your garden, you are required, once made aware of its presence to ensure it is controlled and does not spread onto any neighbouring land. Should the Japanese Knotweed spread onto a neighbouring property, the owner of the neighbouring property can issue legal proceedings against you in a civil court. 

The treatment/eradication of Japanese Knotweed can be extremely expensive and time consuming. Treatment of the weed usually takes place over a course of 3 years and there are no hard and fast guarantees it will not return. 

When purchasing a property, your Surveyor should notify you if there is Japanese Knotweed on the property, or within 7 metres of it. Most lenders are unwilling to lend against property where there is Japanese Knotweed either present within the boundaries, or within 7 metres of the boundaries. 

If you are concerned there may be Japanese Knotweed present on neighbouring property, your first plan of action should be to discuss this with the owner of the neighbouring land to ensure they are made aware of it (if not already) and that they will take measures to prevent it from encroaching on your land.