Japanese knotweed

Japanese knotweed is rarely out of the news. It is the most common of four invasive knotweed plant species in the UK. These are:

  • Japanese knotweed
  • Dwarf knotweed
  • Giant knotweed
  • Bohemian (hybrid) knotweed.

Knotweed can grow in most soil conditions found in the UK, particularly in man-made habitats and it is of particular concern in relation to house sales and purchases.

It is been reported that a homeowner who recently sold a property that was affected by Japanese knotweed was successfully sued by the buyer. The homeowner's legal bill will be £200,000. The buyer did not discover the Japanese knotweed until he worked on the garden and found it growing near to the shed. Japanese knotweed is a plant which can grow very quickly and can cause damage to buildings.

When a person sells their property, they will be asked to complete a Property Information Form which has a specific question about the presence of Japanese knotweed on the property. The seller has the choice of indicating 'yes', 'no' or 'not known'. As can be seen from the recent case, it is very important for the seller to ensure that they receive appropriate advice and answer the questions during the conveyancing process very carefully.

In the recently reported case, the seller indicated 'no' in answer to the question 'is the property affected by Japanese knotweed?'. The court held that this was a misrepresentation upon which the buyer had relied. It can be seen that this cost the seller dear.

A homeowner must stop Japanese knotweed on their land from spreading to other property. Soil or plant material contaminated with invasive plants such as Japanese knotweed can cause ecological damage and may be classified as controlled waste.  As can be seen, the mere presence of the plant on land can cause difficulties with a sale and if it spreads to adjoining land, it could cause a nuisance which could result in legal proceedings.

Japanese knotweed must be removed in an appropriate manner and often involves specialists to remove and dispose of the knotweed followed by land treatment. Many buyers would want such clearance to be backed up by a guarantee. It is thus equally important for the buyer of a property to consider the Property Information Form carefully and to ensure that they receive appropriate advice.