Phone Nav

Japanese Knotweed – is it really that bad?

    Japanese Knotweed – is it really that bad?

    This article on this common plant is written by Nick Bevan of Bevans Chartered Surveyors, providers of commercial property acquisition advice as well as party walls, project management and disabled access consultancy services

    Fallopia japonica (Japanese knotweed) was found in Japan by Phillipe von Siebold and brought back to Europe around 1829. Japanese knotweed is an herbaceous perennial meaning that it dies down to ground level each winter and re-emerges in the Spring, it lasts for an indefinite number of years.

    Japanese knotweed can grow up to 10cm per day, and because of this rapacious growth, it has been known to cause damage to building structures and substructures by targeting weak points, such as cracks in masonry, and attempting to grow through them.

    The best time to spot Japanese knotweed is during mid-summer and early autumn. During spring, reddish/purple shoots appear from the ground rapidly forming dense stands of bamboo-like stems that develop green heart or shield-shaped leaves.

    According to researchers at the University of Leicestershire, people sharing cuttings or disposing of unwanted plants was the “primary pattern of distribution”. It also spread through watercourses, and through the movement of soil for construction and road and rail -building.

    Knotweed costs the UK economy £166 million per year for treatment and in property devaluations, as an example, last year, homeowners Matthew and Suzie Jones were told it would be cheaper to knock down and rebuild their £300,000 London home rather than try and treat their knotweed problem – that saw the familiar red bamboo-like plant grow through their floor. Earlier this year, a man who murdered his wife before killing himself cited the weed that had blighted their West Midlands home as the cause for his mental distress. In a suicide note, lab technician Kenneth McRae, 52, wrote: “I believe I was not an evil man, until the balance of my mind was disturbed by the fact there is a patch of Japanese Knotweed which has been growing over our boundary fence on the Rowley Regis Golf Course.”

    So what is to do? When undertaking acquisition surveys, the presence of Japanese Knotweed is high on our radar when considering environmental threats to a property. Sadly, the existence of this plant is not always obvious depending on the time of year and the accessibility to adjoining premises but if there is an indication that the plant might be affecting the subject building we will identify the risk and recommend the best way to deal with the situation.

    The means of eradication are numerous and each situation will have its own “best” solution in essence however if you suspect this plant might blight your property, speak to an expert, act quickly and don’t ignore its presence.

    Call us on: 01242 584 674
    or Contact Us


    We have used Nick Bevan Consulting for dilapidations, refurbishment and construction advice and each time found that the advice is professional, well considered, and great value for money.

    Elender Properties
    Read more here