Sussex hotspots for Japanese Knotweed and what to do when you spot it

There are a total of 417 infestations of the plant across East Sussex, meaning there is an average of at least one per five kilometres squared in the county.

Hastings is the worst hit area, with 50 infestations and Brighton and Hove are close behind with 48 and 39 respectively.

Rounding off the top five are Crowborough with 34 infestations and 31 in Uckfield.

Environet, the invasive plant specialists, say “vigilance” is the best way to protect your property from the risks posed by Japaneses knotweed.

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Nic Seal, founder of Environet, said: “Vigilance is the best way to protect your property from the risks posed by Japanese knotweed. Make sure you know what knotweed looks like and how it differs from other common garden weeds like ivy and bindweed, so you can keep an eye out for it in your garden and neighbourhood.

“Knotweed is easily identifiable during summer, but as we head through the autumn and into winter, the above-ground growth dies back and it becomes much harder to spot. It’s also easier to conceal, so anyone viewing a property to buy should be extra careful.

“There are lots of horror stories out there but the with professional help, knotweed can be successfully treated and a property’s value can be largely restored.”

This map reveals Japanese knotweed hotspots in East Sussex (Image: Environet)

Japanese knotweed usually emerges in March or April and grows rapidly to reach up to two and a half metres in height by mid-summer.

It is identifiable by its hard, bamboo-like canes and distinctive shield-shaped bright green leaves which grow in a zigzag pattern along the stem.

Tackling knotweed costs the UK economy nearly £250 million a year and homeowners are one of the groups most at risk – not only from potential damage to their property, outbuildings and gardens, which can be costly to repair, but also from legal risks arising from encroachment or when properties are sold. 

Though it is not illegal to have knotweed growing on your land, if it is allowed to cross a boundary into an adjacent property, legal disputes can arise between neighbours.

Similarly, when properties are sold, sellers are asked a direct question about whether knotweed is present, even if hidden beneath the ground or within three metres of the boundary, and those who fail to declare it can be sued by their buyer for misrepresentation.

Environet estimates that approximately five per cent of homes across the UK are currently affected by Japanese knotweed, either directly or neighbouring an affected property, typically impacting property prices by around five per cent - or up to ten per cent in severe cases. 

The invasive plant specialist’s tips are:

• Email a photo of the plant to Environet’s free ID service on email by expert@environetuk.com
• If you are selling your property, inform the estate agent at the outset and even if the infestation is removed, be sure to declare it to potential buyers on the TA6 form.