Enter a postcode to see how many Japanese knotweed sightings have been recorded nearby. The map draws on open biodiversity records, so it shows where the plant has been logged, not a survey of your own plot.
How to read this
The counts and points come from GBIF, the open biodiversity database that gathers records from the NBN Atlas, iNaturalist, the BSBI and local authorities. A high number means knotweed is well recorded in the area. A low number does not prove your plot is clear, because not every stand is reported. If you have found a suspect plant, send us a photo or use our identification guide, and where a sale or mortgage turns on it, book a survey for a documented answer.
To check for Japanese knotweed near you, enter your postcode above. The tool maps every recorded sighting within about 5 km, drawn live from GBIF, the open biodiversity database that gathers records from the NBN Atlas, iNaturalist, the BSBI and local authorities. It is the quickest way to see whether knotweed is known in your area and roughly how widespread it is.
Recorded sightings are a useful first check, but they are not the same as knowing whether your own plot is affected, because not every stand is reported. If the map shows knotweed near you, or you have spotted a suspect plant, the next step is to confirm it: send us a free photo identification, or book a survey where a sale, a mortgage or a boundary dispute turns on the answer. Not sure what you are looking at? Our identification guide shows the signs.
We survey, treat and remove Japanese knotweed across England and Wales. These are the cities we cover most, each with its own local page, recorded sightings map and costed plan.
We confirm the plant, record the RICS category and give you a costed plan.