KIS Bridging Loans
Presented by KIS Finance

What is Japanese Knotweed and where did it come from?

If you haven't heard about Japanese Knotweed before, you'll probably be concerned to learn that having this weed on, or nearby, your property can seriously devalue it, cost thousands of pounds to eradicate, stop you from being able to re-mortgage your property and can even get you an ASBO (anti social behaviour order) if you fail to stop it spreading onto neighbouring properties. It  is a highly invasive plant which can destroy buildings and land if it is not disposed of.

Japanese Knotweed was first introduced into the country during the early to mid-19th Century, originating from Japan, China and Korea, as an ornamental plant for gardens. Since then it has been rapidly spreading and growing all over the country.

Where does Japanese Knotweed grow?

According to Environet Ltd, it is estimated that between 1% and 5% of homes in the UK are affected by Japanese Knotweed - either by having it on their property or on neighbouring land.

It can be found all across the UK but is often found in urban areas, waste land, roadsides, railways and river banks. Certain areas in the UK are affected worse than others – South Wales and London are particularly notorious for Japanese Knotweed.

What does Japanese Knotweed look like?

Japanese knotweed can be identified by the speed at which it grows in the summer, the leaves are mid-green, smooth and a heart/shield shape. It flowers in late summer/early autumn and the petals are creamy white. It can grow up to 3 metres tall, and the shoots start off looking like a reddish coloured asparagus. Here is a picture to help:

Japanese Knotweed

Japanese Knotweed

What damage and problems can Japanese Knotweed cause?

Japanese knotweed is a highly invasive weed and grows extremely fast – this can be up to 10 centimetres a day, especially in the summer. The worst part is the roots - they can grow up to 3 metres underground making it very difficult to remove.

Japanese Knotweed can cause a lot of structural damage to properties and buildings. It can grow through tarmac -  ripping up driveways and landscaping, it can also grow through any cracks in walls or concrete enabling sometimes to grow inside your home as it can also come up through the floor.

How to get rid of Japanese Knotweed

If you suspect you or a neighbour has some of this weed growing, call a professional to come and take a look. They should provide a free report and their proposed treatment plan. If it is not on your land yet, they should advise what you can do to help prevent the weed from reaching your property.

When it comes to removing Knotweed, again you seek professional help as DIY attempts to eradicate the problem can often make the problem worse as even a tiny fragment of the root is able to regenerate and make the weed grow back. There are also rules to follow regarding disposal of the weed once it has been dug up and you could face legal charges if you don’t dispose of it correctly.

Will Japanese Knotweed stop me from selling my home or being able to re-mortgage?

When choosing a professional firm to get rid of the knotweed, make sure you will be covered by their insurance in the event that the knotweed returns. This is important as when it comes to remortgaging or selling your property, mortgage lenders will want to see that the work is covered with an insurance backed guarantee.

Homeowners selling their property have to complete a seller's questionnaire, which contains a question about Japanese Knotweed. It is vital to answer this question honestly, as failure to do so will be seen as misrepresentation and will make you liable for costs incurred due to the knotweed even after the sale. Japanese Knotweed is a 'continuing nuisance' therefore liability for costs and damage after the sale will be down to the new owner.

Finally a bit of good news...

If you live in an area that is at risk, you may want to take out a specialist Japanese Knotweed indemnity policy. This will cover the costs in the event that you are affected by this weed, and depending on the insurer / policy, you may be able to claim back any loss in property value suffered as a result.


Find it useful? Please share!

Subscribe for Updates

We will email you monthly details of our latest:

  • Business and consumer guides
  • Finance news
  • Information and awareness about the latest frauds and scams, to help you avoid them.  
I want to receive email updates

By submitting your email, you agree to our Terms and Privacy Notice. You can opt out at any time.