A NEW map showing all the hotspots where infestations of Japanese knotweed grow on the Isle of Wight for 2023 has been produced.  

Environet — the UK’s leading specialist in the removal of Japanese knotweed and other invasive plants — has analysed nationwide data from an online tracker, that shows Ventnor, Newport, Shanklin, Ryde and Bembridge are worst affected locations on the Isle of Wight.

The Japanese Knotweed Heatmap alerts homeowners and homebuyers to the risk level in their local area. 

Users can enter their postcode directly into the map to discover the number of verified knotweed sightings within a 4km radius, with hotspots highlighted in yellow, orange or, in the worst cases, red. 

They can also add sightings by uploading a photo to be verified by experts.
The Isle of Wight Japanese knotweed hotspots for 2023, with infestation figures, are:

  • Ventnor 54
  • Newport 51
  • Shanklin 47
  • Ryde 31
  • Bembridge 31

With a total of 270 known infestations across the Island, there are 0.7 occurrences of Japanese knotweed in every 1 km².

Japanese knotweed usually emerges in March or April and grows rapidly to reach up to 2.5m in height by mid-summer. 

It is identifiable by its hard, bamboo-like canes and distinctive shield-shaped bright green leaves, which grow in a zigzag pattern along the stem. 

Mature plants flower in August, becoming covered in clusters of delicate, tasselled, creamy-white flowers. 

Knotweed is usually spread accidentally through the movement of soil or garden waste, or via rivers and streams when creeping rootstalk breaks off and takes hold in new locations. 

Tackling knotweed costs the UK economy £250 million a year and homeowners are one of the groups most at risk — not only from potential damage to their property, outbuildings and gardens, but also from legal risks arising from encroachment or when properties are sold. 

Around per cent of homes across the UK are currently affected by Japanese knotweed — either directly, or neighbouring an affected property, which typically impacts property prices by around 5-10 per cent in severe cases.

Nic Seal, of Environet, said: “Vigilance is the best way to protect your property from the risks posed by Japanese knotweed. 

“There are lots of horror stories out there, but the with professional help, knotweed can be successfully treated and a property’s value can be largely restored.”