Is there a map of Japanese knotweed sightings?

Yes. Open biodiversity databases such as GBIF and the NBN Atlas map recorded sightings across the UK. Our knotweed near you tool draws on that data: enter your postcode and it shows the sightings recorded within about 5 km of your address.

How do I check for Japanese knotweed at my address?

A national map shows the broad picture but cannot tell you about one plot, because not every stand is reported. To check your own address, use our postcode checker for recorded sightings nearby, send a photo for a free identification, or book a survey where a sale or mortgage depends on it.

Why does knotweed grow along railways and rivers?

Knotweed spreads mainly from rhizome fragments carried in moved soil and water, so railway lines, riverbanks and canals act as corridors that carry it along. It was also widely planted and dumped near these routes historically, which is why they remain hotspots today.

UK Japanese knotweed map

At SE Knotweed, the knotweed map shows where Japanese knotweed is recorded across the UK alongside the areas we cover, so you can gauge the local picture before booking a survey.

Every area we cover, pinned from its city centre. Select a pin to open that area page. Map tiles © OpenStreetMap contributors.

Where Japanese knotweed is found in the UK

Japanese knotweed is recorded in every part of the UK, so almost no area is entirely clear of it. It was introduced from Japan in the nineteenth century as an ornamental plant and spread from gardens and dumped soil, which is why it now turns up most along railway lines, riverbanks and canals, and on ground where soil has been moved.

Because it spreads from rhizome fragments rather than seed in most of the country, a single stand can travel with fly-tipped or reused soil to a plot that had none before. That is why a local record on a map cannot tell you whether one address is affected. To see the sightings recorded around your own postcode, use our knotweed near you checker. Only looking at the plant itself confirms a stand, which is what our free photo check and a survey are for.

Common questions about Japanese knotweed in the UK

Where is Japanese knotweed most common in the UK?: Japanese knotweed is recorded across the whole of the UK, but it is densest along transport and water corridors, railway lines, riverbanks and canals, and on ground where soil has been moved or fly-tipped. Towns and the sites of old industry tend to show more records than open countryside.
Is there a map of Japanese knotweed sightings?: Yes. Open biodiversity databases such as GBIF and the NBN Atlas map recorded sightings across the UK. Our knotweed near you tool draws on that data: enter your postcode and it shows the sightings recorded within about 5 km of your address.
How do I check for Japanese knotweed at my address?: A national map shows the broad picture but cannot tell you about one plot, because not every stand is reported. To check your own address, use our postcode checker for recorded sightings nearby, send a photo for a free identification, or book a survey where a sale or mortgage depends on it.
Why does knotweed grow along railways and rivers?: Knotweed spreads mainly from rhizome fragments carried in moved soil and water, so railway lines, riverbanks and canals act as corridors that carry it along. It was also widely planted and dumped near these routes historically, which is why they remain hotspots today.

See a stand near you?

We survey, treat and remove Japanese knotweed across England and Wales, and write the plan and guarantee in the form a mortgage lender accepts.

Book a survey