Those looking to buy or sell homes are seeing deals fall through at the last minute upon the discovery of the weed, and others have been told that their homes have plummeted in value after insurers refused to pay out, a BBC programme found.
Matthew and Suzie Jones discovered Japanese Knotweed growing in their house and its value was subsequently cut in half from £300,000.
Speaking to BBC One’s Inside Out programme, Mrs Jones said: “We were told we’d have to have our house torn down. You don’t expect that when you’ve just bought a brand new home. I was in floods of tears.”
Japanese knotweed is difficult to eradicate, not just because of the size and speed at which it grows, but because it can block drains, damage foundations and can grow from a pea-sized amount — much to the frustration of those who have dug up their entire gardens to banish it.
Natalie Waterworth told the programme that she was about to buy her first home when her bank was made aware of Japanese knotweed on the premises and it withdrew the mortgage.
She said: “The knotweed was about 90 feet from the house but in a few weeks it had advanced 60 feet, and then 30. I wouldn’t try to buy a property that has Japanese knotweed — it’s doomed to fail.”
Sue Anderson, from the Council of Mortgage Lenders, said: “It’s an evolving situation. Knotweed has gained so much awareness it can make a prospective property unpopular to buyers. A lender has to consider all these factors.”
To counter the problem, specialist Japanese knotweed agencies are now working with councils, mortgage lenders and homeowners by devising treatment plans backed by warranties to allow sales to proceed.
The Government has estimate that it would cost £1.5 billion to clear the infestations but scientists have recently discovered an insect which feeds on it, which they are hoping to introduce in Britain to eradicate the plant.