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Spring 2021 Japanese knotweed hotspots revealed!

Spring 2021 Japanese knotweed hotspots revealed!


Have you ever wondered if you live in a Japanese knotweed hotspot? Each year, we mine data from Exposed, our online Japanese knotweed heat map which is populated with over 53,000 known infestations, to identify the worst-affected locations.

This year, Bolton tops the table with a whopping 621 infestations within a 4km radius of the city centre, followed by Bristol in the south west and St Helens, Merseyside. The news was covered extensively in the national, regional and broadcast media last week, including this piece on the Mail Online!

Here are the top ten hotspots:

Position                Location  Infestations within 4km radius
1 Bolton, Greater Manchester 621
2 Bristol 465
3 St Helens, Merseyside 440
4 Cardiff, South Wales 419
5 Blackburn, Lancashire 406
6 Llanelli, South Wales 382
7 Swansea, South Wales 320
8 Rotherham, South Yorkshire 320
9 Shepherd’s Bush, West London 230
10 Nottingham 228

This is the time of year when people up and down the country are noticing red or purple asparagus-like stems emerging and rapidly growing into lush green shrubs with heart or shovel-shaped leaves and pink-flecked bamboo-like stems. Following its winter hibernation, Japanese knotweed is entering its spring growth phase, growing by as much as 10cm a day to reach 3 metres in height by mid-summer.

If you’re worried about a suspicious plant in your garden, just email a photo to [email protected] and we’ll identify it for free. If it is knotweed, we can help you put a treatment plan in place to remediate the problem and help protect your property’s value, so you’re in safe hands. Rest assured, Japanese knotweed can always be dealt with. It’s also a good idea to report the sighting on Exposed using the ‘Add Sighting feature’, attaching a photo to be verified by our team. This helps us to build a national picture of the Japanese knotweed problem and keep track of the plant’s spread across the UK.

If you’re buying a property it’s also wise to check Exposed to see whether it’s located in a high-risk area. If it is, you may wish to instruct a professional Japanese knotweed survey, so you know what you’re dealing with. Knowledge is power when it comes to Japanese knotweed, so make sure you’re armed with all the facts – and if the property you’re hoping to buy is affected, you may want to renegotiate the price. Check out our online calculator to get an idea of how the value might be impacted.

To view Japanese knotweed infestations in your area or to report a sighting, visit:

Robert Spaceman

“We had a large stand of bamboo removed, thinned, contained and replaced. The customer service has been first class. Joe and Jason were fabulous and kept me well informed at all times”.