New data has revealed the Cumbria hot spots where the infamous Japanese knotweed is overrun.

The plant is well-known for being Britain's most invasive plant and there are many infestations across the county.

Japanese knotweed has a bad name amongst horticulturists and homeowners alike as the incredibly invasive plant can damage property and land beyond recognition.

The zombie-like plant can grow a whopping 10cm a day between May and July, causing thousands of pounds worth of damage.

The government estimates it would cost £1.5 billion to clear the UK of knotweed and homeowners who fail to stop the spread of the plant on their land can face fines and even jail time under ASBO legislation.

Japanese knotweed heat map of hot spots in Cumbria

As the UK’s most invasive plant enters its spring growth phase, Japanese knotweed expert Environet reveals the latest hotspots using data from its interactive online tracker, Exposed: the Japanese Knotweed Heatmap.

News and Star: The areas of Cumbria being overrun by Japanese KnotweedThe areas of Cumbria being overrun by Japanese Knotweed (Image: Environet)

Users can enter a postcode to discover the number of reported knotweed sightings nearby, with hotspots highlighted in yellow or red.

The Cumbria Japanese knotweed hotspots for 2022 are: Carlisle with 33 infestations in a 4km radius, Maryport with 20, Workington with 16, Whitehaven with 21, Ambleside with 53, Windermere with 28, Kendal with 18, Milnthorpe with 22 and Barrow with 18.

Keswick has 31 within a 4km radius, the village of Cleator has 39 occurrences alone within a 4km radius, as did Frizington with 47 occurrences within a 4km radius.

To view Japanese knotweed infestations in your area or to report a sighting, visit the website here.

How to spot a Japanese knotweed infestation

Following its winter hibernation, knotweed begins to grow in March or April, depending on the local ground temperature, reaching up to 3 metres in height by mid-summer.

Homeowners spending more time in their gardens this spring may notice purple or red asparagus-like shoots now emerging from the ground and quickly growing into lush green shrubs with heart or shovel-shaped leaves and pink-flecked stems.

What effect does it have on your property?

Pushing up through cracks in concrete, driveways, patios, paths, drains and even the cavity walls of our homes, Japanese knotweed can reduce a property’s value by 10 per cent and make it difficult to sell, unless a professional treatment plan is in place with an insurance-backed guarantee to satisfy mortgage lenders.

According to Environet’s research, approximately 5 per cent of homes are currently affected, either directly or indirectly (neighbouring an affected property), knocking around £20 billion off UK house prices.