Worst places for knotweed revealed

IT’S been described as the “UK’s most aggressive, destructive and invasive plant” and can be the scourge of everyone trying to sell their house.

Incredibly hard to control, it can prevent mortgage lenders approving you a loan, impact on the value of your property by up around 10% and even land you with an Asbo.

And now, the 10 places in Wales named the worst for the bamboolike plague that is Japanese knotweed – which can grow 10cm a day in summer months and can reach up to 3m tall – have been revealed.

Provided by Environet UK, the figures show Bridgend is the fifth-worst affected location with 249 infestations within a 4km radius. Carpel Garmon in Conwy is the worst with 395 cases, followed by Llanelli, Caerphilly and Swansea.

Described by the Environment Agency as “indisputably the UK’s most aggressive, destructive and invasive plant”, Japanese knotweed grows rampantly along railways, waterways, in parks and gardens and is notoriously difficult to treat without professional help.

In 2017, two neighbours in Maesteg were awarded damages after Japanese knotweed spread under their properties from a rail line. Stephen Williams and Robin Waistell were awarded about £15,000 each.

Although it looked for a time like they might lose their payout, the Court of Appeal ruled they could keep it, a ruling that meant landowners will be able to claim damages if the “pernicious” invasive weed encroaches on their property.

The Environet UK data comes from an online heat-map which records UK sightings of Japanese knotweed – which first arrived in the UK in the 1840s in a shipment of oriental plant species delivered to Kew Gardens.

The map is intended to inform local homeowners and potential home-buyers of the local presence of Japanese knotweed, enabling them to enter a postcode to discover the extent of the problem near them.