At SE Knotweed, reporting Japanese knotweed means telling the responsible landowner or authority in writing and recording the encroachment, which is the evidence any later nuisance claim relies on.
At SE Knotweed, you report Japanese knotweed by identifying the landowner responsible for the affected land and telling them in writing, with photographs and the date, then keeping a record of what you sent and any reply. There is no single national register, so a report goes to the neighbour, the council, the railway or the highways authority, depending on whose land it is on.
The written report matters because a later nuisance claim needs to show the owner knew of the plant and failed to act, and your letter is the evidence of that knowledge. Confirming the plant first with a survey or a photograph check means you are reporting knotweed and not a look-alike.
You report it to whoever owns the land the knotweed is on: a private neighbour, the local council for council-owned land or a verge, the railway for a lineside embankment, or the highways authority for a roadside. For a stand in your own garden, there is no one to report to, but a survey records it for your own file and any future sale.
Each landowner can be liable in private nuisance where it knew or ought to have known and failed to act, whether it is a person, a council or a railway. Identifying the right owner is the first step, because a report to the wrong party does not help a claim.
Your report should include dated photographs of the stand and where it crosses the boundary, a description of its location, and the date you first noticed it, so there is a clear record of the encroachment and when the owner was told. A survey that confirms the species and maps the extent strengthens it considerably.
This evidence is what a private nuisance claim relies on, because the claim turns on the owner having known and failed to take reasonable steps. Our encroachment claims page sets out what a claim needs, and a CPR Part 35 report presents the technical evidence if it reaches court.
Responsibility for knotweed spreading from next door is a question of private nuisance: your neighbour can be liable where they knew or ought to have known the plant was on their land and failed to take reasonable steps to stop it spreading. The mere presence of knotweed is not enough; it is the failure to act after knowledge that creates the liability.
Published guidance is treated by the courts as the point at which a landowner ought to know, so a written report fixes that date. Our neighbour responsibility page explains how this is judged, and it applies equally to a council or a railway.
If knotweed has spread onto your land you may be able to recover the cost of treating and monitoring it, and damages for the interference with the use of your property, through a private nuisance claim. What you cannot always recover is a residual fall in the property's value, which Davies v Bridgend [2024] UKSC 15 held is not recoverable where the spread happened before the neighbour was in breach.
Claims turn on the facts and on the owner being in breach of a duty, so take legal advice before pursuing one. We provide the survey and, where needed, the expert report the claim relies on, and set out the legal position plainly rather than overstating it.
You deal with your own affected land by getting the stand surveyed and treated even while a claim runs, because leaving it lets the rhizome establish and you still have to declare it when you sell. Treating your side does not weaken a claim; the survey records that the source is next door.
We produce a management plan and, where you proceed, a guarantee a lender accepts, so your own sale is protected regardless of the dispute. Contact us with your address and we will survey the stand and advise on both the remediation and the evidence for a claim.
Tell us the address and what a surveyor flagged. We confirm the plant, record the RICS category and set out the figures.