Alert to UK households as Victorian plant causing ‘enormous damage’ enters growing season

Homeowners are being urged to act quickly over a specific plant. Japanese knotweed is entering its most aggressive growing phase between April and October. Experts warn it can cause “enormous damage” to buildings, gardens and infrastructure if ignored. It was highlighted during an episode of BBC Morning Live this week, where consumer champion Louise Minchin joined presenters Greg Rutherford and Helen Skelton on the sofa to discuss the plant as it surges during peak growing season. Minchin explained that Japanese knotweed is now rapidly re-emerging after winter dormancy, making spring and summer the most important time for identification and control. She said the plant was first introduced to the UK in the mid-19th century as an ornamental Victorian garden species before becoming one of the country’s most destructive invasive plants. The Royal Horticultural Society says Japanese knotweed is now classified as an invasive non-native species that spreads quickly through underground rhizomes and is extremely difficult to eradicate once established. Experts warned it can force its way through patios, pavements, drains and brickwork, with Minchin describing it as a plant that can “turn your life upside down” if not tackled early. The Environment Agency has previously warned that even tiny fragments can regrow, meaning the risk of spreading increases during active growth when homeowners may attempt DIY removal. Property experts say the plant remains one of the biggest concerns in the UK housing market, with mortgage lenders often refusing loans where knotweed is present unless a professional management plan is in place. Research from the Property Care Association suggests treatment programmes can take several years and cost thousands of pounds, particularly when infestations are allowed to develop unchecked. The plant’s underground rhizome system can extend up to three metres deep and several metres wide, allowing it to regenerate even after apparent removal and making summer growth especially difficult to control. Minchin also warned that disposal is tightly regulated in the UK, with contaminated material classed as controlled waste that must be handled by licensed carriers to prevent further spread. Legal experts note sellers must declare Japanese knotweed on property forms, with failure to do so potentially leading to misrepresentation claims and costly disputes over property values. The Property Litigation Association says undisclosed cases can lead to significant legal costs where knotweed impacts sales or requires remedial work. Specialist surveys and trained detection dogs are now being used to identify hidden infestations, including underground growth that becomes more detectable during peak growth periods, experts told Morning Live. The Royal Institution of Chartered Surveyors says eradication is not always realistic, with most cases now focusing on long-term management plans involving herbicide treatment over several growing seasons. Homeowners are being urged to act immediately if they spot signs of knotweed during peak growth, as delays can significantly increase treatment costs and complicate future property sales.