A wet and frosty spring, followed by dry weather and sunshine, has provided it with the perfect growing conditions, according to solicitor Kate Bould, managing director of Index West Midlands.

“Japanese Knotweed is estimated to affect up to 1.45m homes across the UK, which equates to approximately five per cent of residential properties. It can devalue a house by between five and 15 percent, and in some extreme  cases, it has even almost completely devalued properties” she claims.

“Sellers and buyers must realise there is a distinct possibility they will face either a current infestation of the plant, or evidence of it at a property in the past, and that this could halt or totally derail a property sale.

“Home sellers have a legal obligation to declare Japanese Knotweed to buyers. The TA6 Property Information Form used to inform buyers of any negative issues affecting the home, includes a specific question pertaining to Japanese Knotweed.

“Getting a mortgage on a property with or which has had Japanese Knotweed is not straight forward, and in some cases impossible. Most home insurance policies will exclude Japanese Knotweed, and won’t cover owners for damage to their or neighbouring properties, nor the cost of damage to remove or eradicate the plant” she says.

Classified as a ‘controlled waste’ under the Environmental Protection Act 1990, Japanese Knotweed grows up to 20cm a day.

If left unchecked, its deep, wide-ranging roots can tunnel through and destroy foundations, drainage systems, and walls, putting properties at risk of damage as it can grow through cracks in concrete, brickwork, patios, asphalt, cavity walls, gutters, and drains, eventually forcing walls to break apart.

Removal and disposal of it has to be handled by a qualified expert, which depending on the size of the infestation, will cost anywhere between £3,000 and £10,000.

Last week RICS issued advice for the assessment of Japanese Knotweed in UK properties, to help affected homeowners and lenders.