Japanese knotweed in the UK: do you have to remove it, and what the law requires

Japanese knotweed is one of the most troublesome invasive plants in Britain. It is a non-native weed that spreads at great speed, crowds out other plants and can damage paths, walls and foundations. For homeowners it is not just a garden problem but a legal and financial one: knotweed lowers a property's value and complicates a mortgage. Here is what the law requires and how to get rid of it, based on gov.uk.

Do I have to remove it?

By law you do not have to remove knotweed from your land — unless it is causing a nuisance. But there is a strict rule: you must stop it spreading beyond your property. If, through you, it spreads into the wild or onto someone else's land, you can be prosecuted. So even if you leave it in place, it must be watched and contained.

ONLYWAY NEWSLIVEHousing · 05.11Japanese knotweed in the UK: do you have to remove it, and what the law requiresMoney · 05.11UK pension reform: government proposes a 'default pension' for 17 million workersLife · 05.11NHS launches a blood test trial for cancer: 20,000 patients and 200 GP practicesLaw · 05.11County Court Judgment (CCJ) for debt in the UK: what it is and how to clear it from the registerMoney · 04.11Child Trust Funds: easier access to savings for tens of thousandsLife · 04.11NHS breast screening in the UK: who is invited for a mammogram, and how oftenBooks · 04.11Black Beauty by Anna Sewell — a book for the night: the opening, the author and a Norfolk trailLife · 04.11Children's Funeral Fund in England: who qualifies and how to claimTechnology · 04.11GOV.UK Wallet: your documents and driving licence on your phoneLife · 04.11Diabetic eye screening in the UK: who the NHS invites and what happens at the appointmentONLYWAY NEWS · appInstall the ONLYWAY NEWS appFresh UK news, classifieds, key dates and exchange rates on your home screen, one tap away. Free.NewsClassifiedsCalendarRates

Why is it so hard to control?

Knotweed spreads not only by seed but through pieces of rhizome (underground stem): a new plant can grow from a root fragment just 1cm long. That is why you cannot simply dig it up and throw it away — any remaining fragment will sprout again, and contaminated soil can carry it further.

How do you get rid of it?

There are several lawful methods. First, herbicide: stems are sprayed or injected, and it usually takes at least 3 years with repeats, because the roots can lie dormant in the soil. Second, hire specialist invasive-plant removers (check their membership of bodies such as the Property Care Association or INNSA). Third, burial on the same site: you must notify the Environment Agency at least a month beforehand, and the depth is about 5 metres (or 2 metres with a special membrane).

How do you dispose of what you cut?

Cut knotweed and contaminated soil are classed as "controlled waste". You cannot throw them out with ordinary garden waste or surplus soil, and you cannot sell contaminated soil as topsoil. Removal needs a registered waste carrier and a permitted site, and you must tell the Environment Agency where the waste went.

What if it comes from a neighbour?

If the growth comes from next door, the first step is to talk calmly to your neighbour: by law it is they who must stop it spreading. If you cannot agree, it can be handled as a neighbour dispute, up to court. Keep photos and messages — they are useful as evidence.

What to remember

Japanese knotweed is not a reason to panic, but not a problem to ignore either. You do not have to remove it, but you must contain it; digging it up and binning it yourself is risky; herbicide over several years or specialists is safer. The sooner you act, the cheaper and easier it is, especially if you plan to sell.