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Japanese Knotweed – a Knotty Problem


Legal Updates, Property

What is Japanese Knotweed?

Imported into Britain back in the nineteenth century, Japanese Knotweed is one of the most invasive plants in the UK. It can grow up to 10cm a day in the summer, spreading quickly by its roots and stems. It is very difficult to remove entirely from land because it can regenerate from relatively tiny amounts left behind.

What does Japanese Knotweed look like?

Japanese Knotweed can be difficult to identify because it looks a lot like many other weeds.

Some characteristics of Japanese Knotweed that may help you to identify it include:

  • Heart-shaped or shield-shaped leaves
  • Bamboo-like stems (rings round them)
  • An alternating zig-zag leaf pattern
  • Hollow stems with purple speckles
  • Small creamy white flowers during the summer

Japanese Knotweed is commonly confused with Bindweed, Ground Elder and Russian Vine. It is important to research the plant’s characteristics if you suspect that it is growing nearby.

Japanese Knotweed in flower

Why should you be concerned whether your property (or any neighbouring property) is affected by Japanese Knotweed?

  • Japanese Knotweed is invasive and can cause structural damage to buildings, resulting in a negative impact not just on the value and marketability of the property but also its insurability.
  • Japanese Knotweed can be time consuming and costly to treat and manage. It is reported that professional treatment of Japanese Knotweed can be very expensive, ranging from £2,500 and rising to £30,000 for a major infestation.
  • Japanese Knotweed can cause mortgage problems. Historically, there has been reluctance for banks to lend, making it difficult to get a mortgage for a property within 7m of Japanese Knotweed, causing headaches for home owners and prospective buyers.
  • It can lead to criminal and civil liabilities for owners, occupiers and those who handle the Japanese Knotweed if they fail to do so in accordance with the law.

What to do if a neighbour has Japanese Knotweed

If there is Japanese Knotweed on adjoining land, there are several things you can do.

Start amicably and mention the situation to your neighbour, who may not be aware of the issues relating to the plant. Ask if they could seek professional advice for the problem. Follow the conversation up in writing so you have a track record of all communications. It is also worth taking some photos of the land, because you may need these for future reference.

If the situation continues and the Japanese Knotweed spreads to your property, you may need to seek legal advice.

Pre-contract enquiries and the importance of an appropriate survey and inspection relating to Japanese Knotweed

If you are in the process of taking a long lease or purchasing the freehold of property or land, then you should consider whether there is a risk that the property is, or could be, affected by Japanese Knotweed.

In standard residential transactions, the seller is required to provide a completed standard property information form (also known as TA6), which contains an enquiry as to the presence of Japanese Knotweed. In commercial property transactions it is the environmental enquiries that arguably cover the question of Japanese Knotweed.

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There is a potential loophole with residential new-build properties. Developers are not required to complete the property information form, which could leave buyers of new builds exposed. It is therefore important to raise specific enquiries if you have concerns that Japanese Knotweed may be present.

In any event it is likely that the seller may not give a definitive response to such enquiries and the onus may be pushed back onto the buyer to undertake their own inspection of the property/land.

If a buyer is concerned about the presence of Japanese Knotweed, they should consider arranging for a specific survey from a suitably qualified surveyor or environmental consultant.

What should you do if you discoverJapanese Knotweed in your garden?

Firstly, do not try to dig it up. Japanese Knotweed requires specialist waste management. You should contact the Invasive Non-Native Species Association or the Property Care Association (PCA).They can advise you on local removal contractors.

It is important to establish whether any professional you engage in the treatment and removal of Japanese Knotweed offers a suitable guarantee that can be relied upon by future purchasers and mortgage lenders.

There is currently no general duty to control, remove or report the presence of Japanese Knotweed however you may be committing an offence if you fail to take reasonable measures to control the Japanese Knotweed, and or are negligent or reckless resulting in the Japanese Knotweed spreading into the wild.

Japanese Knotweed: UK Law

When it comes to legal obligations relating to Japanese Knotweed, there are two simple points to consider:

  • You can have Japanese Knotweed on your land, but you must not allow it to spread onto adjoining properties. If it does so, it can be considered a civil nuisance and legal action may be taken against you.
  • You must not allow it to spread into wild habitats. You could be fined up to £5,000 or sent to prison for up to five years if this happens.

If you have any concerns or wish to discuss the matters raised further, then please contact our Commercial Property team on 01603 660 811 or email info@hatchbrenner.co.uk.

Japanese Knotweed

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