New Japanese Knotweed alert service highlights risk to property

A new service assessing the risk of the presence of Japanese Knotweed near a property uses a model of the species occurrence and data from the Centre for Ecology & Hydrology and the Botanical Society of Britain and Ireland.

Property search company STL Group is offering the new free alert service when conducting residential searches for conveyancing purposes. Japanese Knotweed is a highly aggressive and destructive plant - the Japanese Knotweed Hazard Alert can immediately inform of the risk of its presence, automatically identifying if the risk is low, medium or high.

Dr Oliver Pescott, a plant ecologist at the Centre for Ecology & Hydrology (CEH), said, “CEH has a long history of working with natural history societies through its Biological Records Centre, and has much expertise in using such data to predict species’ distributions. Recent changes in the law around Japanese Knotweed (Fallopia japonica) have created an interesting opportunity for us to work with new partners in the conveyancing sector and bring a new angle to our ongoing work with the Botanical Society of Britain and Ireland.”

“The species occurrence data collected by the BSBI are generally acknowledged to be amongst the most comprehensive in the world – this has allowed us to create very fine-scale predictive maps of Japanese Knotweed occurrence, and, with input from the conveyancing company STL, produce estimates of Japanese Knotweed risk for the whole of Britain.”

Japanese knotweed stems and leaves

Japanese Knotweed has been described as the UK’s most aggressive and destructive invasive plant. It is a legal requirement to prevent it spreading into the wild and causing a nuisance.

"The species occurrence data collected by the BSBI are generally acknowledged to be amongst the most comprehensive in the world – this has allowed us to create very fine-scale predictive maps of Japanese Knotweed occurrence." Dr Oliver Pescott, CEH

Dr Kevin Walker, Head of Science at BSBI, said, "BSBI volunteers have been recording the spread of Japanese knotweed since it was first recorded in the wild in 1886: this has formed the basis for a substantial body of research into its ecology, spread and invasiveness. Although still relatively uncommon in the wild, it can become very abundant in the right sort of habitat - disturbed places close to habitation where it spreads through the dispersal of root fragments (usually in dumped soil). In these locations, it can exclude all other plants species and cause physical damage to man-made structures such as pavements, walls, foundations, and roads."

Alan Thorogood, CEO of STL Group, said, “Japanese Knotweed is a serious and necessary consideration for conveyancers and we are pleased to offer this new hazard alert service thanks to the input from our scientific partners.”

Innovation and expertise

Nicholas Corker, Innovation Manager at the Centre for Ecology & Hydrology, said, “This kind of activity is an important element of our innovation portfolio. Given the problem of Japanese Knotweed, the STL Group’s new service exemplifies how CEH’s scientific expertise can be utilised by businesses to the wider benefit of society.”

Dr Pescott concluded, “Income from this project will help CEH and BSBI to support the collection of data on our country’s wild plants into the future, with all of the additional benefits that this brings to plant conservation and the study of plant ecology.”

Additional information

The new hazard alert uses an exclusive risk model and data from the Centre for Ecology & Hydrology (CEH) and the Botanical Society for Britain and Ireland (BSBI), in association with STL, to assess the probability of the presence of Japanese Knotweed on a property. This is based on documented occurrences of the plant and environmental factors determining its distribution. The results are indicative and no site visit has taken place.

More details via STL Group: Japanese Knotweed Hazard Alert and Insurance Policy

Gov.uk guidance: Prevent Japanese knotweed from spreading

BSBI website

Staff page of Dr Oliver Pescott, CEH

Biological Records Centre

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