Japanese knotweed and the law: your responsibilities explained
Having Japanese knotweed on your land is not illegal, and there is no legal duty to remove it. But under the Wildlife and Countryside Act 1981 (Schedule 9) it is an offence to plant or "cause it to grow in the wild"; the plant and any soil within 7 metres is classified as controlled waste; and you can be sued in private nuisance — or served a Community Protection Notice — if you let it spread to neighbouring land.
Is it illegal to have Japanese knotweed?
No. It is not illegal to have Japanese knotweed growing on your own land, and there is no legal duty to remove it. The law is about responsibility, not ownership: you must not allow it to spread into the wild or onto a neighbour's land, and you must handle and dispose of any plant material and contaminated soil correctly. Problems — and prosecutions — almost always stem from spread or bad disposal, not mere presence.
The key legislation
Under Schedule 9, section 14 it is an offence to plant or "cause to grow in the wild" — including spreading it through dumped material or moved soil. Penalties reach £5,000 in a magistrates' court, or an unlimited fine and up to 2 years' imprisonment on indictment.
Knotweed, and any soil within 7 metres of it, is "controlled waste". It must be moved by a licensed waste carrier to a permitted landfill, with waste transfer notes kept for at least 2 years.
Councils and police can serve a Community Protection Notice if your knotweed affects others. Ignoring it can bring a £100 fixed penalty, fines up to £2,500 for individuals, or around £20,000 for businesses.
Neighbour disputes & nuisance claims
If knotweed spreads across a boundary, the affected owner can bring a private nuisance claim — and damages are no longer nominal. In Williams v Network Rail (Court of Appeal, 2018) the court confirmed owners can claim even without physical structural damage, and Davies v Bridgend (Supreme Court, 2024) further clarified recoverable losses. Where knotweed sits within 3 metres of a boundary it frequently becomes a conveyancing or lending issue before any physical encroachment.
If it's spreading from a neighbour, raise it in writing first — many disputes resolve once the other party is aware. If not, professional survey evidence is usually essential to a claim.
- ✓Use a licensed waste carrier — check the Environment Agency register
- ✓Dispose only at a permitted landfill
- ✓Keep waste transfer notes for 2 years
- ✗Never bin, compost or burn it
Selling: your TA6 duty
Sellers must answer the standard TA6 Property Information Form question on Japanese knotweed truthfully — including where it has previously been present and treated. An incorrect answer can expose you to a misrepresentation claim long after completion, so disclose it and provide your management plan and guarantee.
Legal FAQs
What is a Community Protection Notice?+
Is Japanese knotweed a notifiable weed?+
Can I be fined for having knotweed?+
Do I have to remove knotweed by law?+
Can my neighbour sue me?+
The key cases in more detail
Two cases shape how encroachment claims work today. In Williams & Waistell v Network Rail (Court of Appeal, 2018), homeowners recovered damages because knotweed spreading from railway land interfered with their enjoyment and the amenity of their properties — even without physical structural damage. In Davies v Bridgend County Borough Council (Supreme Court, 2024), the court further clarified when and how losses (including diminution in value) are recoverable once a landowner is on notice.
The practical takeaway: act promptly once you're aware of knotweed near a boundary, keep written records, and get professional survey evidence — delay narrows your options and increases exposure.
