A Perennial Problem – hiding the presence of Japanese Knotweed

Japanese knotweed was brought to the UK by Victorian Britons as both an ornamental plant and cattle feed. Unfortunately, it also turned out to be an invasive species with no natural UK enemies.

Japanese knotweed growing in the wild or on your land can cause untold damage if left unchecked. It grows at a rapid 10cm per day, into tall and strong cane-like structures which can break through buildings’ foundations and walls and through tarmac, paving and fences. As well as damaging the land it originates from, it can also spread to and damage adjoining properties which could lead to costly legal disputes by affected landowners. Its very presence, and its real risk of significant property damage can reduce the value of the properties blighted – and often significantly reduce a homeowner’s ability to sell their affected property.

Japanese knotweed claims in misrepresentation and nuisance

There are two main areas of law which can lead to the liability of one party not dealing with or disclosing the presence of Japanese knotweed at their property.


A claim in misrepresentation arises where one person makes a statement which is false and which induces another to enter into a contract. Where the presence of Japanese knotweed is known (or ought to be known) by a selling landowner, but it is not disclosed to the property’s buyers when asked, that landowner will become vulnerable to possible claims against him in misrepresentation. A claim could then be brought for all of the costs incurred in removing the Japanese knotweed by an innocent party who relied on the misrepresentation when entering into the contract. The potential costly damage that Japanese knotweed can cause to a property is so extensive that a simple misrepresentation, even if innocently made, can lead to thousands of pounds in damages. Therefore, any representations made (especially at the point of sale of a property) must be carefully considered because they can be relied on months and even several years later.

There have been several recent cases which have favoured Claimants suing former landowners, surveyors and/or current neighbours for failing to disclose or prevent the damage caused by the presence of Japanese knotweed. It is therefore unsurprising to read that the courts have found in favour of yet another Claimant.

In his claim against the former seller of his property, “Mr D” of Raynes Park, London, was awarded £32,000.00 (being the cost to professionally remove and make good any damage caused to his property by Japanese knotweed) as well as £90,000 of legal costs incurred in bringing the claim. Mr D brought his successful claim against “Mr H” for his failure to disclose the presence of Japanese knotweed when directly asked about it before the sale of his property in 2018.

During the purchase of his property, Mr D raised a direct question in the pre-contract enquiries about whether there was any Japanese knotweed present at the property, to which Mr H responded with a simple ‘no’. On completing the sale and moving into the property, Mr D discovered the presence of Japanese knotweed in the garden. In his claim for damages against Mr H, Mr D argued that if Mr H had responded to the initial enquiry raised that he “does not know [whether there was Japanese knotweed present at the property]” then Mr D would have had the opportunity to investigate any issue further. Instead, Mr D was found to have been entitled to rely on the representation given that there was no Japanese knotweed present at the property, which led him to purchase a property incorrectly thinking that it was knotweed free.


Equally as important to consider is the common law claim of “nuisance” that could arise if Japanese knotweed invades a neighbour’s land. A possible claim in nuisance arises when one person does something on their own land which causes a nuisance and adversely affects the owners or occupiers of adjoining land.

Therefore, landowners must also be careful to prevent the presence and spread of Japanese knotweed because the owners or occupiers of neighbouring land may also be able to claim against them for compensation should the presence of Japanese knotweed cause damage or a loss of enjoyment on their own land, a cost to remove it themselves or the cost of seeking an injunction against a landowner to remove the Japanese knotweed (and remedy any damage caused).

In the most notable case of its kind, Network Rail Infrastructure Ltd were found liable to an adjoining landowner to their railway tracks. That adjoining landowner, Mr Wi, brought a claim against Network Rail for failing to deal with the presence of Japanese knotweed which Network Rail had known about for over 50 years at the date of the case. In that case, the claimants owned land which adjoined Network Rail’s railway infrastructure, and the railway embankment and path which led behind the Claimant’s land had been infested with knotweed for 50 years, which had persistently spread and caused damage to the Claimant’s land.

The clear judgment of this case reiterated that by doing nothing to prevent the spread of knotweed, Network Rail were liable in damages to the Claimant. Essentially, in cases of Japanese knotweed and nuisance, it was found that a nuisance can in fact be caused by inaction or omission as well as by positive activity. So it is important to be proactive when it comes to the discovery of Japanese knotweed on your land.

Both of these possible legal claims (both misrepresentation and nuisance) can result in potentially expensive litigation and so it is always better to manage and avoid the spread of Japanese knotweed as soon as possible, rather than risk any future claims in nuisance or misrepresentation. Conversely, if your land is affected by the spread of knotweed form a neighbours land you should also act as quickly as possible.

If you require advice, please do not hesitate to contact us at Herrington Carmichael LLP, we have one of the largest property law teams in the south, alongside dedicated dispute resolution solicitors who have experience in dealing with a variety of disputes in both misrepresentation and private nuisance

Stephen Baker
Partner, Head of Dispute Resolution
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This reflects the law and market position at the date of publication and is written as a general guide. It does not contain definitive legal advice, which should be sought in relation to a specific matter.

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