Japanese Knotweed – Not just a gardener’s nightmare.

Japanese Knotweed is classified as a highly invasive, fast-growing plant that poses a significant risk of property damage. If left untreated, it can exploit weaknesses in such things as brick, tarmac and metal piping. It has the capability to regrow from cuttings as small as 2mm and can grow at a rate of 10cm a day, making its removal challenging.

Identifying Japanese Knotweed can be difficult, as it resembles many native plants. When selling a property, the seller is legally required to declare in the TA6 Property Information Form whether Japanese knotweed is present at the property. Most of us remain unaffected by Japanese Knotweed, so when it comes to selling your home the usual response to this question is ‘No’ but we are here to tell you why that one simple answer could cost you a lot of money.  

In the case of Downing v Henderson, Mr. Henderson’s response of ‘No’ to the Japanese Knotweed query resulted in a legal dispute with the buyer, Mr. Downing. Despite Mr. Henderson’s genuine lack of awareness of the plant, the Judge ordered him to pay £32,000 in damages, covering the investigation, removal of the plant, and the property’s diminished value. Mr Henderson was also liable for Mr Downing’s legal costs which totalled £95,000.

So, what should you do when selling a property? The moral of the story is that unless you can say with absolute certainty that Japanese Knotweed is not present at the property, your answer should be ‘NOT KNOWN’.

Additional Risks and Legal Considerations

The risks associated with purchasing of a property with Japanese knotweed include the difficulty of removal and its potential to cause property damage. Furthermore, the individual with Japanese knotweed on their property can be held liable if it spreads to neighboring properties or land, resulting in fines up to £2,500 based on the Antisocial Behaviour Order (ASBO).

Removing Japanese Knotweed is not often a DIY task due to its extensive root system. It is considered controlled waste, and according to the Environmental Protection Act (Duty of Care) Regulations, 1991, it must be disposed of safely at a licensed landfill site.

Mortgage lenders often require a formal Japanese knotweed removal plan from a professional contractor to meet mortgage requirements. Home removal methods are usually insufficient. A recommended approach is to conduct a Japanese Knotweed survey on the property to assess the extent of the issue and determine the best course of treatment, which may include herbicide sprays, stem injections, or physical excavation and safe disposal.

Author: Megan Wood – Trainee Solicitor – Litigation.

If you have any questions in relation to this article or require advice in relation to the topics discussed, please contact Ruth McKenzie at [email protected]