Home owners planning to sell this summer are being urged to check their land for Japanese knotweed before beginning to market their properties and consult a residential conveyancing solicitor .

If a property is known to have the invasive plant, lenders are likely to reject a mortgage application for it and insurance companies may refuse to provide cover because of the potential damage which the fast-growing knotweed can cause in undermining foundations and drains.

It is easier to identify the plant in summer when it has creamy-white flowers and eradication is not as lengthy when the weather is dry. However, removing the knotweed requires a combination of specialist weed killer and excavation and is likely to take months rather than weeks.

Chartered surveyors who fail to note the plant when making a valuation or full survey may become the subject of a professional negligence claim if they do not report its existence and, as a result, a mortgage offer or insurance cover is withdrawn.

Jim Gibson, of the Royal Institute of Chartered Surveyors in Scotland, said, "Japanese Knotweed can be exceptionally problematic for property owners, largely due to mortgage lenders generally refusing to lend to properties with knotweed in existence.

"In particular, chartered surveyors need to be very vigilant when conducting home reports as they could potentially be pursued for damages if knotweed is found on the property yet not reported, resulting in expected mortgage or insurance covers being withdrawn."

Other laws have been amended and introduced to combat the spread of this damaging plant whose range now extends throughout the UK, apart from the far north of Scotland. There is a large area of growth around the Olympic Games site in east London.

A home owner with Japanese knotweed may also fall foul of the Wildlife and Countryside Act, which contains a clause that anyone spreading the plant is committing a criminal offence. Therefore, any excavated soil contaminated by the weed must be disposed off at a licensed landfill site.

If cuttings, roots or other parts are disposed of in ordinary rubbish or compost, the person concerned can be prosecuted for breaching the 1990 Environmental Act. Breaking this law can lead to an unlimited fine for the person concerned.

Legal advice for developers, landowners and both potential and existing home-owners with a Japanese knotweed problem is available from residential conveyancing lawyers.