Battle to clear development site of Japanese knotweed

Course of treatment ‘successful’ says East Devon District Council.

East Devon District Council has employed experts to rid the Beehive development site in Honiton of Japanese knotweed.

The weed, a bamboo-like perennial plant which can grow by as much as 10cm a day, now “only covers a small area”, a spokeswoman for the council told the Midweek Herald.

An eradication programme has been ongoing since 2004 to clear boundaries of Dowell Street car park of the plant, it has been revealed.

Experts say the weed can grow through concrete, damaging buildings and roads.

Japanese knotweed has been found at several locations along the banks of the River Gissage, in Honiton, prompting homeowners to fear its presence could interfere with insurance claims.

The Royal Institution of Chartered Surveyors (RICS), which produced an in-depth report on the effects of Japanese knotweed on property, says it cannot comment on individual cases.

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However, its report states: “Most buildings insurance policies do not cover damage and problems caused by Japanese knotweed.

“Additionally, because the damage occurs gradually, it is unlikely to be covered in the future.

“Where Japanese knotweed originates from a neighbouring property, insurance companies are likely to pursue others for the costs of the damage caused.”

RICS says treatment options for a typical property may cost up to �5,000 and take more than three years to be successful.

If excavated, the weed must be treated as contaminated waste.

East Devon District Council told the Herald: “There has been an eradication programme since 2004 to deal with the Japanese knotweed at Dowell Street car park.

“Each year, in late summer, our contractors, who are experts in this area, deal with the problem.

“Their efforts have been very successful so that the knotweed now only covers a very small area of the site.”

The council added: “It is not illegal to have Japanese knotweed on your property, but it is illegal to allow it to spread off your property.”

If not properly treated, segments of the plant can remain dormant in soil for 20 years before producing new plants.