Homeowners are being reminded to look out for Japanese knotweed as it emerges in spring
Its spread needs to be stopped(Image: imageBROKER/Alf Jönsson via Getty Images)
Householders are being urged to watch out for Japanese knotweed, as it starts to appear in spring and blooms in summer. With many uncertain about its appearance, the plant can readily go undetected until it develops into a more serious issue.
Matthew Harwood, home insurance specialist at Confused.com, explained: “Japanese knotweed can be tricky to spot, and it’s often mistaken for plants like Himalayan balsam or giant hogweed. Our research shows that only one in four (26%) UK homeowners or renters actually know what Japanese knotweed is, yet nearly one in five (18%) say they’ve been affected by it.
“But there are some key signs to look for. It typically has spade-shaped leaves with a pointed tip, and grows quickly once the weather warms up. If you discover Japanese knotweed on your property, there’s no legal obligation to remove it. However, you do have a duty to prevent it from encroaching onto neighbouring properties.
“The longer it’s left untreated, the more it can spread and the more expensive it becomes to deal with. Our research shows removal costs can reach up to £1,910 on average, so acting early and seeking professional help can save you money in the long run.
“Home insurance doesn’t usually cover the cost of removing Japanese knotweed itself, but you may be covered for damage it causes, depending on your policy and whether you’ve taken steps to control it.
“It’s important to declare it when taking out insurance, as failing to do so could risk future claims being rejected. Our guide on Japanese knotweed damage explains how to identify the plant, what risks it poses, and the best ways to remove it.”
Japanese knotweed rules
According to gov.uk, Japanese knotweed is the most prevalent of four invasive knotweed plant species in the UK. These are Japanese knotweed, dwarf knotweed, giant knotweed and bohemian (hybrid) knotweed.
Knotweed can thrive in most soil conditions found in the UK, particularly in man-made environments, such as roadsides, waste ground, railway embankments and cuttings and spoil tips that are made up of waste material from mining or quarrying. It’s also frequently found along rivers and streams.
Knotweed spreads through direct rhizome (root) growth and new plant growth from the parent plant’s stem and rhizome fragments – a new plant can grow from pieces of rhizome as small as 1cm.
If you have knotweed on your land or property
You must prevent Japanese knotweed on your land from spreading beyond your property.
Soil or plant material contaminated with non-native and invasive plants like Japanese knotweed can cause ecological damage and may be classified as controlled waste.
You do not legally have to remove Japanese knotweed from your land unless it’s causing a nuisance, but you can be prosecuted for causing it to spread into the wild.
