Do you live in a Japanese knotweed hotspot? The interactive map shows where the plant is blooming

Japanese knotweed is a devastatingly invasive plant that can leave homeowners and gardeners in a bind.

The fast-growing grass was brought to Britain by the Victorians as an ornamental garden plant and to line railway tracks to stabilize the soil.

While it is controlled by fungi and insects Asiait has no natural enemies in the UK, where it can wreak havoc on gardens.

Now, Environet’s invasive plant specialists have revealed that the areas in the UK that suffer the most from Japanese knotweed infestations.

Their results show that Bolton, Bristol, St Helens and Blackburn top the list of UK weed hotspots.

Environet researchers revealed that the areas in the UK that suffer the most from Japanese knotweed infestations

Environet researchers revealed that the areas in the UK that suffer the most from Japanese knotweed infestations

The hotspots of the Japanese polygon of the United Kingdom

  1. Bolton, Greater Manchester (684 infestations)
  2. Bristol (475)
  3. Saint Helena, Merseyside (441)
  4. Blackburn, Lancashire (407)
  5. Capel Garmon, Snowdonia, Wales (398)
  6. Llanelli, South Wales (389)
  7. Cardiff, Wales (361)
  8. Rotherham, Yorkshire (306)
  9. Streatham, South West London (300)
  10. Nottingham (225) and Sheffield (225) =

Environet has developed an interactive map called “Exposed: The Japanese Knotweed Heat Map”where users can explore how many infestations have occurred in their area.

“With the Japanese polygon growing season now well underway, we pulled data from our interactive online tracker, Exposed: The Japanese Knotweed Heatmap, to reveal the national range hotspots for 2022,” he explained.

Populated with nearly 55,000 known occurrences of polygon, exhibited is the most comprehensive online record of polygon infestations, tracking the spread of the plant across the country.

“Just enter your zip code to find out the number of sightings nearby, with hotspots highlighted in yellow, orange and, worst case, red.”

The data shows that Bolton is the area with the highest number of cases, with as many as 684 infestations within a 2.4 mile (4 km) radius.

Bristol (475 infestations), St Helens (441 infestations) and Blackburn (407 infestations) are next on the list, followed by Capel Garmon (398 infestations), Llanelli (389 infestations) and Cardiff (361 infestations).

Finally, Rotherham (306 infestations), Streatham (300 infestations), Nottingham (225 infestations) and Sheffield (225 infestations) complete the top 10.

The Japanese shooting range is incredibly resilient and fast growing, and can severely damage buildings and construction sites if left unchecked.

Capable of growing eight inches in one day, it deprives other plants of their key nutrients and water.

“In winter the plant dies back to ground level, but in early summer bamboo-like stems emerge from the rhizomes deep underground to reach over 2.1m (7ft), suppressing all other growth. plants, “explained the Royal Horticultural Society.

If you suspect you have Japanese knotweed in your garden, luckily there are several things you can do to get rid of it.

Data shows Bolton is the area with the highest number of cases, with 684 infestations within a 2.4 mile (4 km) radius.

Data shows Bolton is the area with the highest number of cases, with 684 infestations within a 2.4 mile (4 km) radius.

St Helens had 441 infestations in 2022, according to Environet

The data shows that Bristol suffered 475 Japanese polygon infestations

Bristol (475 infestations), St Helens (441 infestations) and Blackburn (407 infestations) are next on the list, followed by Capel Garmon (398 infestations), Llanelli (389 infestations) and Cardiff (361 infestations).

Organic methods include digging the plant out of the ground or removing all leaves to prevent the plant from photosynthesizing.

However, these methods can take years to take effect, and you will need to check the plant regularly to remove new leaf shoots when you see them.

The other option is a chemical method, for which you will need to get an expert.

“A glyphosate-based herbicide is the best option here, although keep in mind that it may take several applications, up to four seasons, to completely eradicate the Japanese knotweed,” advises Gardeners’ World.

“It is best applied to cut the canes so that the herbicide can fully penetrate the plant and roots.”

The new interactive map of Environet arrives shortly after a the study revealed that invasive species, including the Japanese knotweed, have cost the UK economy more than £ 5 billion over the past 50 years.

The Japanese shooting range is incredibly resilient and fast growing, and can severely damage buildings and construction sites if left unchecked

The Japanese shooting range is incredibly resilient and fast growing, and can severely damage buildings and construction sites if left unchecked

While previous research has shown that invasive species can have a big economic impact, researchers at Queen’s University in Belfast set out to figure out how much damage they have suffered in the UK.

Dr Ross Cuthbert, Research Associate at Queen’s University Belfast School of Biological Sciences, said: ‘We found that most of the costs were caused by direct damage, such as reduced agricultural productivity and infrastructure repair costs. , while very little has been spent on the effective management of invasive species, and above all on the prevention of future invasions.

‘Worryingly, we have also found that invasion costs are increasing rapidly over time and are likely to continue to increase in the future as more invasive species arrive in the UK.

“These costs are also seriously underestimated, as very few of the invasive species known in the UK have reported economic costs (less than 10%), indicating a lack of research efforts and reporting of their harmful impacts.”

What is the Japanese polygon?

The Japanese knotweed is a species of plant that has bamboo-like stems and small white flowers

The Japanese knotweed is a species of plant that has bamboo-like stems and small white flowers.

Native to Japan, the plant is considered an invasive species.

The plant, scientific name Fallopia japonica, was brought to Britain by the Victorians as an ornamental garden plant and to line railway tracks to stabilize the soil.

It has no natural enemies in the UK, while in Asia it is controlled by fungi and insects.

In the United States, it is considered an invasive weed in 12 states and can be found in 29 others.

It is incredibly durable and fast growing and can severely damage buildings and construction sites if left unchecked.

The infamous plant strangles other plants and can kill entire gardens.

Capable of growing eight inches in one day, it deprives other plants of their key nutrients and water.