Japanese Knotweed, Giant Hogweed and Himalayan Balsam may sound like exotic plants but they are on a list of invasive weeds that can cost landlords an anti-social behaviour order and thousands of pounds in fines if they fail to keep them under control.

Giant Hogweed is considered a health hazard as sap coming into contact with the skin can lead to blisters in bright sunlight.

Japanese Knotweed and Himalayan Balsam are invasive and can undermine buildings but are not toxic.

Local councils and government agencies are trying to stem the spread of invasive and destructive weeds – and landlords who ignore control orders to clear up their properties could go before the courts and face having an ASBO slapped on them and fines of up to £2,500.

Weed control experts also claim buy to let mortgage lenders are turning down loan applications if the plants are too near rental homes.

The Property Care Association (PCA) claims lenders are rejecting mortgage applications when invasive weeds are growing near a rental property without contacting weed control specialists, which breaches guidelines set by the Royal Institution of Chartered Surveyors (RICS).

Stephen Hodgson, the PCA chief executive, said:

“Mortgage lenders should follow the advice set out by RICS. It seems unjustifiable to Japanese Knotweed control specialists that lenders continue to decline loans where weeds are classified as dangerous to the structure of a building without first seeking the views of a suitably trained, experienced and qualified specialist.

“The line taken by a few lenders seems unnecessarily harsh and ignores the recommendations as they are set out in the RICS guidance paper.”

“Where treatment plans are provided by a specialist guarantees and assurances are usually provided to the property owner that the treatment was successful. These guarantees can be insured in most cases.”

Besides ASBO laws, European Union rules which came into force in January 2015 penalise landowners with fines of several thousand pounds if invasive plants are left unmanaged.