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Japanese knotweed and the law in the UK

Having knotweed isn't a crime - but there are real legal duties around it. Here's what UK law actually says about spreading it, disposing of it, your neighbours, and selling a home affected by it.

Updated July 2026 · 6 min read

Dead-looking Japanese knotweed canes in winter over a living rhizome
Even dormant, knotweed is controlled waste - how you handle it is governed by law.
The quick version: It's not illegal to have knotweed on your land. Causing it to grow in the wild is a criminal offence under the Wildlife and Countryside Act 1981 - but a neighbour's garden isn't "the wild": letting it spread next door is a civil matter, a private nuisance claim. The waste is controlled waste and must be disposed of properly, a community protection notice can compel you to act, and when selling you must declare it honestly.

Is it illegal to have Japanese knotweed?

No. There's a persistent myth that knotweed on your property is against the law - it isn't, and you won't be prosecuted simply for having it. What the law regulates is how you deal with it: causing it to grow in the wild, letting it encroach on a neighbour, how you dispose of the waste, and what you declare when you sell.

It's worth separating two things that often get muddled together. Causing knotweed to grow in the wild is a criminal offence. Letting it spread into a neighbour's garden is a civil matter - private nuisance. They're different laws, different consequences, and a neighbour's garden is not "the wild".

1. Causing it to grow in the wild - Wildlife and Countryside Act 1981

Under Section 14(2) of the Wildlife and Countryside Act 1981, it is a criminal offence to plant or otherwise cause Japanese knotweed to grow in the wild. In practice that means things like fly-tipping cuttings or contaminated soil, or moving it onto a verge, riverbank, woodland or waste ground.

The words in the wild matter, and they are where most confusion starts. A neighbour's garden is not "the wild", so knotweed creeping under a garden fence is not a Wildlife and Countryside Act offence. That situation is a civil matter - see below.

2. Letting it spread to a neighbour - private nuisance

This is the one most people are actually asking about, and it is a civil claim, not a crime. If knotweed encroaches from your land onto next door, you can be liable in private nuisance - a claim your neighbour brings in the civil courts, not something the police prosecute.

The Court of Appeal confirmed in Network Rail v Williams (2018) that knotweed encroaching on a neighbour's land can be an actionable nuisance because of the way it interferes with their use and enjoyment of their property. A claim usually turns on whether you knew, or ought reasonably to have known, that it was there and failed to act - which is exactly why a dated identification is worth having.

3. Disposing of it - controlled waste

Japanese knotweed, and any soil containing its rhizome, is classed as controlled waste under the Environmental Protection Act 1990. That means:

  • It can't go in your household bin, green-waste collection or home compost.
  • It must be removed to a licensed landfill or treated on-site by a specialist under the correct controls.
  • Improper disposal can lead to enforcement action and penalties.

4. Anti-social behaviour powers

Under the Anti-social Behaviour, Crime and Policing Act 2014, councils and the police can issue a Community Protection Notice (CPN) requiring someone to control knotweed that's having a detrimental effect on the local area - for example, by letting it spread to neighbours. Failing to comply with a CPN is a criminal offence and can result in a fine.

5. Selling a property

When you sell, the TA6 Property Information Form asks whether the property is affected by knotweed. You must answer honestly - a knowingly false answer can lead to a misrepresentation claim. See our guide to knotweed, mortgages and house sales.

Note on nations: the core rules apply across England, Wales and Scotland, but some specifics and enforcement differ. Scotland has its own provisions under the Wildlife and Natural Environment (Scotland) Act. Always check the position for your area.

Do you have to remove it?

No - there's no legal duty to remove knotweed from your own land. But given the duty not to let it spread, the effect on property sales, and the rising cost of treatment as it grows, dealing with it early is almost always the sensible choice.

Confirm it, then document it

A dated identification protects you - whether you're selling, talking to a neighbour or planning treatment. Get a verdict in seconds with KnotweediD, plus an optional PCA CSJK accredited surveyor's report.

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Frequently asked questions

Is Japanese knotweed illegal in the UK?

Not to have it - but it's an offence to cause it to grow in the wild, and the waste must be disposed of as controlled waste.

Can I be forced to remove it?

Not from your own land, but a community protection notice can require you to control it if it's affecting others.

What happens if my neighbour lets it spread to me?

You may have a nuisance claim - see your rights when a neighbour has knotweed.

Alexander White, PCA Certificated Japanese Knotweed Surveyor
Written by Alexander White PCA Certificated Japanese Knotweed Surveyor (CSJK) About our surveyors →

This is general information about UK law as at 2026, not legal advice. Legislation and enforcement vary between England, Wales, Scotland and Northern Ireland and can change. For a specific situation, consult a solicitor and a PCA-accredited specialist.