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Does my home insurance cover Japanese knotweed?

Most of us have heard of the notorious Japanese knotweed. But fewer of us fully understand the destruction it can cause.

If you own a property, it’s worth making sure you can recognise this non-native weed – and find out if your home insurance covers any damage it causes.

Most of us have heard of the notorious Japanese knotweed. But fewer of us fully understand the destruction it can cause.

If you own a property, it’s worth making sure you can recognise this non-native weed – and find out if your home insurance covers any damage it causes.

Written by
Anna McEntee
Insurance comparison expert
Reviewed by
Kate Hughes
Insurance expert
Last Updated
9 MARCH 2023
5 min read
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What is Japanese knotweed?

Japanese knotweed is a weed that was introduced to Britain back in 1825 as an ornamental plant. Little did they know… The plant soon started taking over gardens and proved almost untameable.

Japanese knotweed can grow to over two metres high. Its roots can spread seven metres in all directions and can even break through tarmac. You don’t want to underestimate this plant.

What should I do if I find Japanese knotweed?

If you find Japanese knotweed, it’s important to take action straight away.

It’s a good idea to get a professional in to deal with it. While tackling Japanese knotweed yourself might be cheaper in the short term, you could end up inadvertently spreading it if you don’t know what you’re doing.

The seeds aren’t fertile in the UK, so Japanese knotweed spreads through its roots. It’s not enough to dig it up – if you leave even just one centimetre, it can grow into a new plant.

Can I get in trouble if I have Japanese knotweed in my garden?

Yes. Although it’s not illegal to have Japanese knotweed in your garden, if you let it spread to a neighbour’s garden, they could sue you under the private nuisance act.

And if you’re thought to be spreading Japanese knotweed into the wild, you could be fined up to £5,000 or imprisoned for up to two years. You could also be served a community protection notice.

Do I need to inform my insurance provider if I have Japanese knotweed?

You’re not obliged to tell your insurance provider if there’s Japanese knotweed on your property unless they specifically ask you about it. But if they do ask, you must be honest and tell them.

Will having Japanese knotweed affect my premiums?

Having Japanese knotweed shouldn’t affect your home insurance premiums. But that’s only because your policy probably won’t cover removing the plant or making good any damage it causes.

Can Japanese knotweed cause property damage?

Yes. This is the problem – Japanese knotweed can grow through materials as hard and dense as tarmac, which means it can damage homes with structural weaknesses, affecting drains or fragile walls. The worst cases can even cause subsidence.


The good news is that in January 2022, the Royal Institution of Chartered Surveyors (RICS) declared that the plant posed little to no threat to structurally sound properties.

Will my insurance provider pay for treatment of Japanese knotweed?

Most home insurance policies don’t cover the cost of treating or removing Japanese knotweed, so you’ll need to sort this out yourself – and it’s probably best to hire a professional.

Am I covered for damage caused by Japanese knotweed?

Probably not. In most cases it’s unlikely that a claim for damage caused by Japanese knotweed would be covered under a home insurance policy. Most policies won’t cover you for damage that happens gradually over time.

If you have Japanese knotweed and do nothing about it, an insurance provider could claim the damage is due to your own negligence and failure to act.

What if I hired a professional to get rid of Japanese knotweed and it came back?

That’s between you and the company. If they promise you the plant has gone and won’t reappear, you’ll need to call and ask them to revisit your property.

Can I be held responsible if Japanese knotweed spreads to my neighbour’s house?

It’s certainly possible, yes. If you have Japanese knotweed, don’t keep it under control and it spreads into neighbouring gardens, then you could be held responsible for any damage it causes. 

Your neighbours might seek compensation to cover the cost of any damage, as well as the impact on their property value. If you have legal cover as part of your home insurance, you may be able to get legal advice or help through your insurance provider.

Will my insurance cover legal expenses if my neighbour takes action?

Your home insurance may cover you for legal costs if your policy includes legal assistance in the event of a legal case being taken against you.

You can choose legal expenses insurance as an add-on to your home insurance. Make sure you read the terms and conditions of your legal assistance contract carefully and discuss them with your provider before instructing a lawyer – because legal costs can rack up fast.

Looking for a suitable policy for you and your home? Compare home insurance in minutes to see if you can save.

Frequently asked questions

What does Japanese knotweed look like?

Japanese knotweed has tall, purple-flecked stems and shovel-shaped leaves. It produces white flowers in late summer. Chances are, you’ve seen it on wasteland or by the side of railway tracks.

How long does it take to treat Japanese knotweed?

It can take three years to treat Japanese knotweed, as you’ll need to keep retreating it with chemicals. And never disturb or relocate the soil as this can cause it to regrow.

How do I dispose of Japanese knotweed?

It’s not easy to get rid of Japanese knotweed. If you bury it, you’ll need to do so at a depth of at least two metres, and you’ll need to inform the Environment Agency first.

If you burn it, you’ll need to check with your local council that this is allowed. That’s why it’s better to get an expert involved.

How do I find a company that specialises in treating knotweed?

If you’re trying to find a company to help you get rid of Japanese knotweed, it’s worth contacting the Trade Body for Invasive Species Experts or the Property Care Association.

I recently bought a property that has Japanese knotweed. Can I claim compensation?

If your new property has Japanese knotweed and you weren’t told about this during conveyancing, you may have grounds to claim compensation. In this case, it’s worth seeking independent legal advice.

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Anna McEntee - Insurance expert

Anna’s all about delivering fantastic insurance products at a great price. Value is the most important thing for Anna, as she cuts through the jargon and finds what’s most important and worth your hard-earned money.

Learn more about Anna

Kate Hughes - Insurance and finance expert

As an award-winning journalist, author and broadcast commentator, Kate has been writing about personal finance for more than 20 years. She’s the former Money Editor for The Independent. Her work has appeared across the UK broadsheets as well as a number of international titles. Kate brings her financial expertise to inform her readers on ways to save money. She’s also written a book. ‘Going Zero: One Family’s Journey to Zero Waste and a Greener Lifestyle’ is available now.

Learn more about Kate

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