Japanese Knotweed – The Legalities

March 12, 2017

Japanese knotweed (Fallopia japonica) is a hardy, fast growing plant Native to Japan, East Asia, China and Korea. Originally introduced to the UK for ornamental garden purposes, knotweed has now spread out of UK gardens and was first recorded in the UK wild in 1886. It is able to grow in any soil type, no matter how poor, and has thrived in the UK climate since its introduction. It is able to grow up to 2m tall in one growing season, spreading a root and stem system 3m deep and 7m across. The root system is capable of penetrating tarmac and brickwork, inflicting significant damage to building foundations and drainage systems as well as having an impact on the biodiversity of indigenous plants and wildlife. For these reasons Knotweed is now designated as an invasive species in the UK.

How to Identify and Remove Knotweed

Knotweed can be identified during its growing season (March-September) by its lush green leaves that have a shield like appearance and extend from a ‘zig-zag’ type arranged stem. The main bamboo like stems display purple speckles. The Government’s advisory page (at the bottom of this article) links to www.nonnativespecies.org where further details on how to identify the plant can be found.

Whilst Knotweed can be removed from land, this is a costly undertaking whether it is done through the complete excavation and disposal of the contaminated soil or through the repeated application of glyphosphate-based weed killers over several growing seasons. Whatever method is used a budget of several thousand pounds (£5000 – £10,000 depending on area) will be required and this will not take into account the cost of any repairs to damaged infrastructure.

Obligations and Legalities

Sellers are now obliged to confirm the presence of knotweed, where it is within their knowledge, via the Law Society’s Property Information Form (TA6). Nevertheless it is important that a prospective purchaser make their own inspection, and instruct their own professional survey, as the potential repercussions of finding Knotweed on your land can be serious.

Whilst it is not an offence to have Knotweed in a garden, the Anti-Social Behaviour, Crime and Policing Act can be used to compel land owners to remove Japanese Knotweed where its presence is causing nuisance or damage to neighbouring property. This is achieved through the issue of a Community Protection Notice by the Police or, more commonly, the Local Authority.

Breaching the terms of such a notice is a criminal offence subject to a fixed penalty notice, itself attracting a penalty of £100, or prosecution. Subsequent prosecution can lead to a level 4 fine (currently up to £2500).

Planting or otherwise encouraging the growth of knotweed in the wild is an offence under section 14(2) of the Wildlife and Countryside Act 1981. Anyone convicted of an offence under Section 14 of the WCA 1981 may face a fine of £5,000 and/or 6 months imprisonment, or 2 years and/or an unlimited fine on indictment.

As an added complication knotweed is classified as “controlled waste” under the Environmental Protection Act 1990, and for practical purposes most individuals will need to dispose of knotweed, and the vast quantity of contaminated soil, at a licenced landfill site at further expense. The Environment Agency’s Code of Practice for managing and removing knotweed can be found through the Government’s advisory page.

Mortgage lenders do instruct their Valuers to report to them where Knotweed is present and reserve the right to refuse a mortgage where it is found. Alternatively a lender may place financial restrictions on the mortgage advance pending the professional removal of the knotweed at yet further expense to the purchaser. This will normally prompt a renegotiation on any agreed sale price.

In the unfortunate event that a buyer unknowingly purchases a property with knotweed present there may be legal courses of action available. These can include a professional negligence claim against the surveyor if they have overlooked the presence of the knotweed or against the seller for misrepresentation if they have deliberately hidden, or failed to disclose, knotweed where they knew it to be present. Legal advice should always be sought under these circumstances as each case will depend on the specific circumstances and information available at the time of the purchase.

Further information can be found at https://www.gov.uk/guidance/prevent-japanese-knotweed-from-spreading

The information provided in all of our blogs reflects only a narrative of some elements to consider on the topic. The blogs do not contain considered legal advice and should not be relied upon as advice. Please see our website terms and conditions for full details of our disclaimer. If you are interested in obtaining advice, please contact one of our lawyers who will be happy and able to advise you on your own particular circumstances.

By clicking “Accept All Cookies”, you agree to the storing of cookies on your device to enhance site navigation, analyse site usage, and assist in our marketing efforts. View our Privacy Policy for more information.