The recent UK storm season could lead to a bigger infestation of Japanese knotweed – the notorious problematic and invasive plant – according to Japanese knotweed specialists.
Days after wreaking havoc across the UK, severe and widespread flooding from the trio of named storms – Storms Dudley, Eunice and Franklin – is feared to have bigger consequences than expected.
The storms, which wreaked havoc across the British Isles last week, continued to cause flooding which could have long-term consequences as the unintended spread of notorious weed species. With over 60 different flood alerts and warnings released nationwide, there is a great risk of Japanese knotweed spreading to areas previously beyond its reach, the website claims.
The invasive weed, described by the Environment Agency as ‘unquestionably the most aggressive, destructive and invasive plant in the UK’, has recently been the subject of advice and guidance updated by the Royal Institution of Chartered Surveyors (RICS).
Adam Brindle, managing director and founder of Japanese Knotweed Specialists, said the urgency of dealing with suspected cases of Japanese knotweed where it could invade your property “remains a key priority”.
“As a highly invasive species, the UK government has identified Japanese knotweed as a weed that needs to be professionally treated to prevent its spread. It is estimated that up to 1.45 million homes in Britain could be affected by this invasive species, which has a reputation for being difficult to kill.”
He said Japanese knotweed is often found along riverbanks, where soil containing root fragments breaks off and moves downstream on currents, which often then spill into nearby land.
“Even these small pieces of root can take hold, allowing knotweed to grow and spread. In areas affected by extreme flooding, the spread of Japanese knotweed can be accelerated beyond its already high rates. Natural disasters such as floods and storms encourage Japanese knotweed to take hold in areas it previously could not reach,” Brindle added.
He warned homeowners should be careful as flooding after Eunice, the worst of three storms, may have been another catalyst for the spread of Japanese knotweed.
“But it’s not just low-lying areas that are at risk, as Japanese knotweed rhizomes – the root system – wash into previously unaffected properties, creating new infestations in different parts of the country,” he said. he continued.
From spring to summer, Japanese knotweed grows through the ground in the form of bamboo-like stems, reaching up to 3 m (9.8 ft).
“Alarmingly, in high season, Japanese knotweed shoots can grow up to 10cm per day,” Brindle explained. “If left unchecked by a specialist, Japanese knotweed can grow through cracks and vulnerabilities in concrete, hard ground and, in the worst case scenario, destabilize foundations. Knotweed treatment is essential, as an uncontrolled infestation can be extremely costly. »
According to Brindle, this makes identification an essential first line of defense. Common red flags include hollow bamboo-like canes, an aggressive growth habit, and a zigzag appearance. Using a Japanese Knotweed Image Gallery can help in the identification process, but investors should use a professional service to perform a full investigation and report for official confirmation of “this highly invasive and harmful plant.”
“Make no mistake if you live outside areas known to have infestations because if you’ve recently had flooding it’s worth looking for any red flags where knotweed has been spread by recent UK weather events. United,” Brindle concluded.
“Even if you suspect Japanese knotweed is growing in your garden, DIY removal may be ineffective, as only small traces of root fragments are enough to regrow or your treatment could cause the knotweed to spread further. Japanese knotweed removal team should be notified immediately if the weed is suspected of affecting your property.”