Legal Issues with Japanese Knotweed

It has been illegal in the UK since 1981 to plant or otherwise cause Japanese knotweed to grow. Because of its highly regenerative nature, knotweed is classed as ‘controlled waste’ and disposal of any knotweed material beyond the boundaries of the site of origin runs the risk of prosecution if it is not disposed of by prior arrangement at a licensed landfill site (except in very rare circumstances where the Environment Agency has formally granted otherwise). The transportation of knotweed to landfill and the herbicidal treatment of knotweed on site are also subject to various legal and best practice requirements. There are a number of pieces of legislation that relate to Japanese knotweed and it is important to familiarise yourself with them to ensure you do not inadvertently break the law.

The following is a list of the principal legislation that impacts upon the treatment or removal of Japanese knotweed. It is not an exhaustive list, as pieces of legislation are often being updated or superseded, but serves as guidance to the most relevant.

Control of Pesticides Amendment Regulations 1997 (amendment to COPR 1986)
The Wildlife and Countryside Act 1981 (as amended)
The Environmental Protection Act (1990)
The Environmental Protection (Duty of Care) Regulations 1991
The Controlled Waste (Registration of Carriers and Seizure of Vehicles) (Amendment) Regulations 1998
The Hazardous Waste Regulations 2005
The Waste Management Licensing Regulations 1994

Japanese knotweed spreading across property boundaries is an all too common problem. In these situations, property owners often consider bringing legal action against their neighbours, where their neighbour can be identified as a source of the infestation now encroaching on their land. None of the above legislation covers this circumstance, so the usual routes of action are to seek a prosecution under Common Law or to request an Anti-Social Behaviour Order to be issued under The Anti-Social Behaviour, Crime and Policing Act 2014.

The Anti-Social Behaviour Orders may be implemented by either Local Authorities or the local Police Force and the process can be initiated either directly by these bodies or by a ‘community trigger’, whereby a group of individuals bring a claim of nuisance against a single party. While the legislation does not specifically refer to Japanese knotweed, guidance issued by the Home Office in 2014 suggested it could be included. The legislation itself is open to interpretation, meaning each Council or Police Force will have their own locally defined trigger points, with action only being taken after these have been fulfilled. This does mean that some regions will be much more proactive with this legislation than others.

Common law case against Network Rail

Under Common Law, legal cases involving knotweed tend to be heard in the civil court. Many civil cases never reach court due to the claimant running out of money or an out of court settlement being reached between the parties involved. Generally, civil cases are not reported in the wider media, but one case from 2017-8 caused national headlines and has changed the legal landscape in regard to knotweed infringement.

Neighbours Stephen Williams and Robin Waistell brought individual actions against Network Rail in regard to encroachment of knotweed onto their properties in Maesteg, South Wales. The case (reference B2OYX969) was first heard in Cardiff County Court in February 2017, with judgement being found in favour of the claimants. The case established that the mere presence of knotweed on Network Rail’s land was an actionable interference with the use and enjoyment of the claimant’s land. As a result, Network Rail were ordered to pay damages for the cost of treatment and the residual diminution in value of the claimant’s property after the treatment had been carried out. Network Rail appealed this decision, but the County Court upheld the original judgement (case reference B34YJ849).

This led to Network Rail taking their appeal to the High Court (Network Rail Infrastructure Limited (Appellant) v Stephen Williams and Robin Waistell (Respondents) [2018]). The result of the appeal was announced in early July 2018. The Court of Appeal unanimously upheld the original County Court judgement, though held that claimants cannot claim private nuisance purely on the basis of diminution of the property. It did, however, state that the encroachment of knotweed rhizomes imposes an immediate burden on land owners, who would face an increased difficulty in their ability to develop their land as a result should they wish to do so. Consequently, Japanese knotweed can be seen as affecting a land owner’s ability to fully use and enjoy their property and can therefore be deemed to interfere with the land’s amenity value.

High Court judgements can lay the foundations for legal precedents and so this case has opened the floodgates for other actions against land owners who do not control the spread of knotweed from their land. This judgement holds such land owners to account and imposes a positive duty on them to control their knotweed. Failure to comply with this obligation may result in awards for damages for the treatment costs and nuisance caused.

While this will undoubtedly result in more cases of this kind being heard, it is important to recognise that no legal case has any guarantee of success and professional legal advice should always be sought before embarking on such an action. Even a win in the courts will prove expensive in solicitor’s fees, etc. Wherever possible, voluntary co-operation between neighbours is always preferable to formal legal proceedings. If legal action is inevitable, The Knotweed Company can provide an expert witness to outline the issues involved to the Court and its officials.

Other Invasive Weeds

Aside from knotweed, there are other invasive weeds that are subject to legislation. Giant hogweed in particular is a significant issue and is subject to most of the same legislation as Japanese knotweed. The following publication provides useful reading for issues arising from giant hogweed, including history, biology, treatment and the health implications the plant presents. See also our giant hogweed section in ‘Other Invasive Weeds’.

Giant Hogweed Management in the United Kingdom by Olaf Booy and Max Wade (2007)

Common ragwort, whilst a native species to the UK, causes a great deal of concern, particularly in regard to the health of livestock. Generally, the rule of thumb with ragwort is that it must be dealt with if it presents a significant risk of infecting livestock fodder but can be left alone if it does not. The management of ragwort is detailed in the following guidance document:

The Ragwort Code of Practice 2004

If you are looking for general information on a wide range of invasive species affecting the UK, you may find the following publication useful:

Field Guide to Invasive Plants and Animals in Britain by Olaf Booy, Max Wade and Helen Roy (2015)

Further general information and treatment advice on a range of invasive plants can be found in the following:

Practical Management of Invasive Non-Native Weeds in Britain and Ireland by the Property Care Association (2018)

Please note that The Knotweed Company provides links to external websites in good faith and is not responsible for either the link or any information obtained from these links.