Homeowners are being advised to take prompt action regarding a particular plant. Japanese knotweed is now entering its most aggressive growth phase from April to October.
Experts caution that ignoring Japanese knotweed can lead to significant damage to buildings, gardens, and infrastructure. The issue was discussed on a recent episode of BBC Morning Live, where consumer advocate Louise Minchin, along with hosts Greg Rutherford and Helen Skelton, highlighted the plant’s surge during the peak growing season.
Minchin emphasized that Japanese knotweed is rapidly resurfacing after winter dormancy, underscoring the importance of identifying and controlling it during spring and summer. Originally introduced to the UK as a Victorian garden species, Japanese knotweed has evolved into one of the most destructive invasive plants in the country.
The Royal Horticultural Society classifies Japanese knotweed as an invasive non-native species that spreads rapidly through underground rhizomes and is notoriously difficult to eradicate once established. Experts warn that it can penetrate patios, pavements, drains, and brickwork, with Minchin describing it as a plant that can wreak havoc if not addressed early.
The Environment Agency has previously cautioned that even small fragments of Japanese knotweed can regenerate, heightening the risk of spread during active growth stages when homeowners may attempt DIY removal.
In the UK housing market, Japanese knotweed remains a major concern, with mortgage lenders often refusing loans if the plant is present without a professional management plan. Research indicates that treatment programs can span multiple years and entail substantial costs, especially when infestations are left unchecked.
The plant’s underground rhizome network can extend up to three meters deep and several meters wide, allowing it to regenerate even after apparent removal, particularly challenging during summer growth. Minchin also highlighted the strict regulations for disposal in the UK, categorizing contaminated material as controlled waste that must be managed by licensed carriers to prevent further spread.
Legal experts stress that sellers must disclose Japanese knotweed on property forms, as failure to do so could lead to misrepresentation claims and disputes over property values. Undisclosed cases can result in significant legal expenses when the presence of knotweed impacts sales or requires remedial action.
Specialist surveys and trained detection dogs are now employed to identify hidden infestations, including underground growth that becomes more noticeable during peak growth periods. The Royal Institution of Chartered Surveyors notes that complete eradication is often impractical, with focus shifting to long-term management plans involving herbicide treatment over multiple growing seasons.
Homeowners are strongly advised to act promptly upon spotting signs of knotweed during peak growth, as delays can escalate treatment costs significantly and complicate future property transactions.