Japanese knotweed: The property-wrecking plant invasion threatening Northampton property prices

Experts warn it spreads like wildfire, grows 3m tall and can wreck drives, drains and walls

By Kevin Nicholls
Thursday, 6th May 2021, 1:09 pm
Watch out for asparagus-like shoots in your garden — because it's Japanese knotweed and could wind up 3m tall
Watch out for asparagus-like shoots in your garden — because it's Japanese knotweed and could wind up 3m tall

Homeowners are being warned about a property-wrecking plant that could wipe ten per cent off the value of their property.

Experts say Japanese Knotweed in the UK's most invasive plant and has a fearsome reputation for spreading like wildfire.

Unchecked, it can push through cracks in concrete, driveways, paths, patios and drains — and even in the walls of homes, making them tough to sell.

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Northampton and Higham Ferrers have been identified as two hotspots in the county, with 39 known infestations according to Japanese knotweed experts Environet.

Regional director Mat Day said: “Knowledge is power when it comes to Japanese knotweed and this heatmap is invaluable to homeowners and buyers who want to assess the risk in their local area.

"With the stamp duty holiday extended and lockdown restrictions beginning to ease, the property market is busier than ever – but failing to carry out the appropriate checks for knotweed can turn out to be an expensive mistake.

“With professional help, the plant can be dealt with and the value of a property largely restored.

"I’d urge anyone buying or selling a property, or homeowners wishing to preserve the value of their home, to be vigilant for signs of spring growth and check our interactive online tracker Exposed to see if they live in a high-risk area.”

Following its winter hibernation, knotweed begins to grow in March or April, depending on the local ground temperature, reaching up to three metres in height by mid-summer.

Homeowners spending more time in their gardens this spring may notice purple or red asparagus-like shoots now emerging from the ground and quickly growing into lush green shrubs with heart or shovel-shaped leaves and pink-flecked stems.