The plant is rapidly regrowing after lying dormant throughout winter, with experts warning the invasive plant can cause “enormous damage”
Louise Minchin talking on BBC Morning Live about Japanese knotweed(Image: BBC)
Homeowners are being told to take action as soon as possible with Japanese knotweed reaching its most damaging growth period from April through to October. Experts warn it can inflict “enormous damage” on properties, gardens and infrastructure if left unchecked.
The matter was highlighted during a BBC Morning Live broadcast on Thursday, May 7, where consumer champion and former BBC Breakfast host Louise Minchin appeared alongside presenters Greg Rutherford and Helen Skelton to address the plant as it thrives during its peak growing months.
Minchin outlined that Japanese knotweed is now quickly re-emerging following its dormant winter phase, making spring and summer the most critical time for spotting and managing it. The species was initially introduced to Britain in the mid-19th century as a decorative Victorian garden plant before becoming one of the country’s most damaging invasive species. The Royal Horticultural Society confirms that Japanese knotweed is now categorised as an invasive non-native plant that spreads aggressively through underground rhizomes and proves exceptionally challenging to eradicate once established.
Specialists cautioned it can penetrate through patios, pavements, drains and brickwork, with Minchin characterising it as a plant that can “turn your life upside down” if not addressed promptly. The Environment Agency has previously cautioned that even the tiniest pieces can regenerate, meaning the danger of proliferation increases during active growth periods when householders may try to tackle it themselves.
Property experts say the plant continues to be one of the most pressing issues in the UK housing market, with mortgage providers regularly refusing loans where knotweed is detected unless a professional management scheme has been put in place, reports the Express.
Studies from the Property Care Association suggest that treatment plans can extend over several years and cost thousands of pounds, especially when infestations are allowed to spread without intervention. The plant’s subterranean rhizome network can extend up to three metres in depth and several metres in width, allowing it to regenerate even after seeming removal and making summer growth especially difficult to control.
Minchin also warned that disposal is tightly controlled in the UK, with contaminated material designated as controlled waste that must be managed by licensed carriers to prevent further spread. Legal experts also highlight that sellers are required to disclose Japanese knotweed on property documentation, with failure to do so potentially leading to misrepresentation claims and expensive disputes regarding property valuations.
The Property Litigation Association cautions that undisclosed instances can result in considerable legal expenses where knotweed impacts sales or requires remedial action. Specialist assessments and specially trained sniffer dogs are now being used to track down hidden infestations, including below-ground growth that becomes simpler to spot during peak growing periods, experts told Morning Live.
The Royal Institution of Chartered Surveyors maintains that total removal is not always possible, with most cases now focusing on long-term management approaches involving herbicide treatment over several growing seasons. Homeowners are being strongly urged to act straight away if they spot any evidence of knotweed during peak growth, as postponing action can significantly increase treatment expenses and create difficulties with future property sales.
