An interactive map has revealed the Japanese knotweed hotspots across the UK, including in Bolton.

The latest data from Environet shows how many infestations of the plant have been recorded in the county.

Some areas are known to have more Japanese knotweed than others – let’s take a look.

What is Japanese knotweed and why is it a problem?

Japanese knotweed is an invasive plant that can cause chaos in our homes and gardens.

The Bolton News: Across Greater Manchester there are 2.2 occurrences of knotweed in every 1km2Across Greater Manchester there are 2.2 occurrences of knotweed in every 1km2 (Image: Environet)

The plant “is a fast-growing and strong clump-forming perennial, with tall, dense annual stems. Stem growth is renewed each year from the stout, deeply-penetrating rhizomes (creeping underground stems).

“Although originally introduced to Britain as an ornamental garden plant, Japanese knotweed is an invasive non-native species”, explains The Royal Horticultural Society (RHS) website. 

Japanese knotweed hotspots in Bolton

According to Environet, Japanese knotweed has been found in Bolton – 1,010 infestations to be exact.

You can view the interactive heat map and enter your postcode here to see where the hotspots are.

Other infestation hotspots in Greater Manchester include Manchester where 532 have been reported.

In Bury, 258 infestations have been recorded while Wigan has 239.

Skelmersdale is also a hotspot with 191 Japanese knotweed infestations.

Bolton is the second worst affected location in England and Wales after Swansea.

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Nic Seal, founder of Environet, said: “At this time of year knotweed has emerged from the ground and by the end of April or early May it will be growing as much as 10cm per day and covered in bright green heart-shaped leaves.

“The best way to protect your property is to make sure you know what knotweed looks like, so you can act early if it appears in your garden or is threatening to encroach onto your property.

“Yorkshire is home to some significant knotweed hotspots such as Rotherham and Sheffield. Anyone living near or moving to one of these areas should check their garden carefully and enter their postcode into Exposed to find out how many occurrences are nearby and if in doubt, seek expert help.”