FRESH data has revealed the areas in Essex being blighted by Japanese knotweed following infestations across the UK.

The invasive plant species grows four inches a day in summer, with its roots spreading far underground causing structural damage to buildings.

It is also responsible for damaging homes, pavements and drains and can spread up to seven metres horizontally.

As Japanese knotweed’s summer growth period draws to a close, invasive plant specialist Environet has analysed the latest data from its live online tracker to reveal this year’s Japanese knotweed hotspots.

There are currently almost 58,000 known infestations in the UK.

Across Essex, there is a total of 338 known infestations, with one occurrence of Japanese knotweed in every 10km².

Colchester is the worst affected, with 44 infestations.

Other badly affected areas are Chelmsford and Westcliff with 33 and 28 infestations respectively.

Echo: Here are the Japanese Knotweed hotspots in EssexHere are the Japanese Knotweed hotspots in Essex (Image: Environet)

What is Japanese Knotweed?

Japanese knotweed usually emerges in March or April and grows rapidly to reach up to 2.5 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.

Mature plants flower in August, becoming covered in clusters of delicate tasselled creamy-white flowers.

Knotweed does not produce viable seeds as all the plants in the UK are female, so it is usually spread accidentally through the movement of soil or gardening waste, or via rivers and streams when pieces of rhizome break off and take hold in new locations.

What to do if you spot Japanese Knotweed?

  • Email a photo of the plant to Environet’s free ID service at

  • Commission a professional Japanese knotweed survey to confirm the extent of the infestation, where it originated and the best way to treat it.

  • Put a professional treatment plant in place.

  • If you’re 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.

  • If you’re unsure whether your property or one you wish to buy is affected by knotweed, commission a survey. Experts will check the property and its immediate surroundings for any sign of the invasive plant.

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