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Invasive Plants Check

Check any UK property for all notifiable invasive plant species. Searches open source records within a 5-mile radius — covering Japanese knotweed, giant hogweed, Himalayan balsam, and more.

Data sourced from publicly reported sightings. Most infestations are recorded, but a physical invasive plant survey is recommended for certainty.

Invasive Plants FAQ

Which invasive plants does this check cover?

This tool checks for seven property-relevant invasive species: Japanese knotweed, giant hogweed, Himalayan balsam, rhododendron ponticum, floating pennywort, New Zealand pygmyweed, and cotoneaster. All appear on Schedule 9 of the Wildlife and Countryside Act 1981 (as amended), which makes it an offence to plant or cause them to spread in the wild.[1]

Are all invasive plants as serious as Japanese knotweed?

Japanese knotweed is the most mortgage-relevant invasive plant — lenders specifically flag it. The others are less likely to affect mortgage availability but can still have legal, environmental, and financial implications. Giant hogweed is also dangerous due to its toxic sap. All should be disclosed on the TA6 form if known.

What if a species shows "No data"?

No data means no formal sightings have been recorded in open source databases for that species within the 5-mile search radius. It does not guarantee absence — infestations on private land or in gardens are frequently never formally reported. A physical invasive plant survey from a PCA-accredited contractor is the only way to confirm a property is clear.

Do invasive plants need to be disclosed when selling?

Yes — all known invasive plants must be declared on the TA6 property information form under environmental matters. Failure to disclose is misrepresentation and can lead to legal claims from buyers after completion. This applies even to treated, historical infestations.[2]

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Homedata API Scientific, granular measurements

Exact sighting counts and closest recorded distance in metres for all 7 notifiable invasive species within the 8km search radius — the raw data behind every detection result, per species.

Structured as JSON · queryable by UPRN or postcode · ready to embed in any application

Exact measurements

Real values — distances, concentrations, counts — not rounded ratings

29M+ UK properties

Every address queryable by UPRN or postcode

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What is an invasive plants check?

An invasive plants check searches biological recording databases for sightings of notifiable invasive species within a radius of a UK property. Homedata aggregates open source records from the NBN Atlas and other biological databases to return per-species counts and distances for the 7 most property-relevant invasive plants in the UK.

The 7 species covered

  • Japanese knotweed — the most mortgage-relevant invasive plant; lenders specifically flag it when within 7m of the boundary
  • Giant hogweed — dangerous due to toxic sap that causes severe burns; most common along riverbanks
  • Himalayan balsam — spreads rapidly along watercourses; less of a mortgage issue but must be controlled and disclosed
  • Rhododendron ponticum — problematic in woodland and rural properties; can damage tree roots and habitats
  • Floating pennywort — aquatic; relevant for properties adjacent to rivers, ponds, or drainage ditches
  • New Zealand pygmyweed — aquatic; similar relevance to floating pennywort
  • Cotoneaster — widely grown as garden plant but several species are notifiable as invasive non-natives

Legal obligations

All notifiable invasive non-native species are subject to restrictions under Schedule 9 of the Wildlife and Countryside Act 1981. It is an offence to plant or allow them to spread. Sellers must disclose known invasive plants on the TA6 property information form — failure to do so is misrepresentation. This applies even to treated, historical infestations.

Data sourced from open biological recording databases under OGL. Last reviewed: May 2026.