£18,000 Japanese Knotweed warning as cases expected to rise

Japanese knotweed can cause a nightmare for homeowners and can stop you from being able to sell your home

Discovering Japanese knotweed on your property can quickly escalate into an expensive nightmare that can hinder you from selling your home or securing a mortgage.

The plant proliferates rapidly and can inflict damage to buildings, plus it’s incredibly tough to eliminate.

Typically, if you spot the weed, you’ll need to call in the professionals who will apply a specialist treatment to exterminate the plant roots.

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It’s not usually a one-off visit and they’ll have to return to ensure the plant is dead.

These costs can accumulate to thousands of pounds.

Japanese Knotweed can grow up to 10cm a day in the summer and reach heights of up to 7ft.

The robust plant establishes deep roots which can extend to around three metres, impacting foundations and buildings.

You can face prosecution for causing knotweed to spread into the wild, if you have not taken care to remove it.

Regulations surrounding the plant mean it is illegal to ignore it and let it spread to any other property, and you can be fined up to £2,500 if you fail to do so.

Once the plant has been removed, its presence must be disclosed to future buyers, which can affect prices in the future.

Matthew Harwood, home insurance expert at Confused.com says: “It’s expected that the rise of Japanese knotweed could soon increase, as it begins to emerge in spring and flower in summer.”

You are responsible for the removal costs and any damage it causes to neighbouring properties, so it’s best to get it treated as early as possible to prevent any fu.

Further payouts for damages may be necessary. “Seeking professional help is the best option, and removal costs roughly £1,000 per square metre. While it is expensive, it is the most effective method of removal.”

According to the Office for National Statistics, the average garden size in the UK is approximately 188 square meters. This means that if knotweed takes root in even a small portion of your garden, the costs can quickly escalate.

For instance, if knotweed infests just a tenth of your garden, you could be looking at around £18,000 for removal.

If the plant causes damage to your property, you’ll also need to factor in repair costs. Matthew points out that home insurance typically does not cover these expenses.

However, this shouldn’t impact your ability to secure coverage.

He advises: “If you are affected by Japanese knotweed then you should declare it when taking out a policy, otherwise you could risk any future claims being rejected, even if it’s unrelated to damages caused by the weed. If you do try to claim for damages caused by the weed, then this will depend on your efforts to control it.”