What To Do If A Seller Lied About Japanese Knotweed

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Buying a house is one of the most stressful experiences a person can go through, from sorting out mortgages to arranging moving dates and exchanging contracts. By the time you finally have the keys to your house you expect the stress to be over. However, this is not always the case. Sometimes new problems can be lurking right outside your front door.

Japanese Knotweed is an invasive weed that first appeared in the UK in the 1850s and has continued to wreak havoc ever since. The plant can grow into cracks and crevices within a house and cause structural damage from the inside.

Due to the destructive nature of the weed, the legislation and laws surrounding it are very clear. If you allow Japanese Knotweed to grow outside of your property and into the wild you can face prosecution.

Within this article, we will be looking at what Japanese Knotweed is, the effects it can have on a property, and what you can do if a seller lied about Japanese Knotweed on their property.

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What Is Japanese Knotweed?

As we have already discussed, Japanese Knotweed is an invasive weed and it can grow up to 10cm a day. Because of this rapid growth, it can cause damage to properties by targeting weak points, such as cracks, and attempting to grow through them.

Typical damage from Japanese Knotweed includes:

  • Structural damage to building foundations
  • Destruction to retaining wall
  • Damage to tarmac and paving
  • Reduction in property values

Whilst it is a menace to your home, the weed has other uses aside from devaluing homes. The flowering plant can be used for medicine to treat bronchitis, cough, gum disease, and sore throats. It has also been used to help treat skin disorders, lung diseases, and fluid retention.

However, no matter how useful this plant is, it does not change the structural damage it can do to your home.

Where Can You Find It?

Japanese Knotweed can be found in a variety of locations across the UK. It can be found in most soil conditions, especially in man-made habitats.

  • Roadsides
  • Railway embankments and cuttings
  • Waste ground
  • Spoil tips made of waste material

It is also often found by rivers and streams.

It can spread in two key ways, either through direct root growth or through rhizome fragments. A rhizome is a continuously growing horizontal stem and knotweed can grow from a rhizome as small as 1cm.

Do Sellers Have To Disclose Japanese Knotweed?

If a seller lied about Japanese Knotweed and has failed to disclose its presence on their property, they have broken the law.

The Independent reported that 75% of buyers were put off a property after they discovered the presence of Japanese Knotweed.

When selling a property, sellers are required to disclose whether Japanese Knotweed is present on their property through a TA6 form. A TA6 form is a property information form that is used for conveyancing and in 2013 it became a legal requirement for Japanese Knotweed to be disclosed through this form.

On a TA6 form, there is a specific question regarding Japanese Knotweed. The form asks “is the property is affected by Japanese Knotweed?”. The seller has three options, ‘yes’, ‘no’, and ‘not known’.

Keeping in mind the damaging effects Japanese Knotweed can have on the structural integrity of a house and in turn on house prices, it is unsurprising to learn that some sellers may lie about the presence of the weed in order to help the house sale progress.

Sellers that lie about the presence of the invasive weed risk serious complications which may end up costing them a lot more than the quick sale they wanted ever could make them.

What To Do If A Seller Lied About Japanese Knotweed

If a seller lied about Japanese Knotweed on the TA6 form, then they have lied on a legally binding document and are liable for a lawsuit.

Some mortgage lenders will refuse to lend to a property who have Japanese Knotweed within 7 meters of their home. Because of this, it is easy to see why some sellers attempt to lie about or hide the presence of Japanese knotweed on their property.

If you have found Japanese Knotweed on your property then you have several options for how you can proceed. You can bring a claim against the sellers for misrepresentation, negotiate on price, get a specialist in for treatment or treat the Japanese Knotweed yourself.

The first thing you can do is bring a Japanese Knotweed specialist in to look at the infestation and to conduct a survey, detailing the location and extent of the Knotweed, as well as any other relevant information they may unearth.

Bring A Claim:

If a seller lied about Japanese Knotweed and has checked ‘no’ on the TA6 form, you may be able to claim for compensation on the grounds that the property has been misrepresented to you. You can claim on the grounds that you would not have purchased the property had you been made fully aware of its condition.


If the seller has misrepresented the house by checking the ‘no’ option on the form they will more than likely not want to go to court. If this is the case, you could try negotiating with the sellers to see if they will cover the cost of treatment.

Rather than having to go to court, paying legal fees, and dealing with the stress, the sellers may be convinced that settling out of court is the way to go.

How To Treat Japanese Knotweed

If you have found yourself in the position of purchasing a home with Japanese Knotweed, there are many treatment options for you to choose from.

Specialist Treatment:

The most highly recommended treatment option for Japanese Knotweed is to bring in a licensed professional. Due to the difficult nature of the weed, your best chance of successfully removing it comes from specialist treatment.

The exact cost of treatment depends on the severity of the case. Typically a herbicide treatment and monitoring program can cost between £2000-£3000 to possibly tens of thousands should the knotweed need to be excavated.

If you do decide to use a licensed professional, they should be a member of an accredited body and come with a 10-year insurance-backed guarantee to prove that the problem is being dealt with in a professional manner.

If you decide that you do not want to bring in a professional, legally you can tackle the problem yourself, however, it is not advised. If you do decide to tackle the issue yourself, then there are a few options.


One option for getting rid of Japanese Knotweed is to spray it with chemicals. The chemicals used must be approved herbicides and will need to be reapplied. It normally takes at least three years to effectively treat Japanese Knotweed. The Knotweed rhizome can lay dormant for many years and can regrow if it is disturbed or if the soil is relocated.

Bury It:

Another option for the disposal of Japanese Knotweed is to bury it. If this is the route that you wish to choose, you must notify the Environment Agency at least one month before you bury the knotweed.

You can use composting on-site as a way to get rid of the brown canes of the Japanese Knotweed, as long as they are cut a minimum of 10cm above the crown.

If you are going to bury knotweed material, you must remember to bury it on the site it came from with any ash and soils containing potential knotweed propagules.

If you have not sealed the knotweed remains with a material called geotextile membrane it must be buried at a depth of at least 5 meters. If you have sealed it with a geotextile membrane, then it must be buried at a depth of at least two meters.

When burying Knotweed with any geotextile membrane, it is worth checking that it is:

  • Undamaged
  • Sealed securely
  • Large enough to minimise the need for seals
  • Will remain intact for 50 years
  • UV resistant

It is strongly recommended that you use a contractor with experience burying Knotweed. You should always check that they are part of an assured scheme, such as one with a relevant trade body.

Burn It:

Another way that you can dispose of Japanese Knotweed is to burn it. If you are an individual who wants to burn it, you only need to check with your local council that burning is allowed. However, if you are a business that wishes to burn Japanese Knotweed, you must first complete the following:

  • At least a week before you burn it, you must inform the Environment Agency
  • Tell the environmental health officer at your local council
  • Acquire a burning waste in the open exemption (a D7 exemption)
  • Follow local Byelaws

If you decide to burn the Japanese Knotweed, it is worth remembering that Knotweed crowns and rhizomes can survive the burning so you must follow the correct procedures for how to bury it or dispose of it off-site.

This covers just about everything you need to know about what to do if your seller lied about Japanese Knotweed If you have any questions or queries, or any insight on the matter, please feel free to get in touch!

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photo of Alexandra Ventress

Alexandra is a junior content producer who enjoys writing articles and finding out more about the property market. Read more about Alexandra here.

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About Alexandra Ventress 91 Articles
Alexandra is a junior content producer who enjoys writing articles and finding out more about the property market. Read more about Alexandra here.

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