Japanese Knotweed a Real Bind!

Japanese Knotweed Phil Keddie Sunshine Rentals Epert Property Lettings Consultant

Once considered a Victorian ornamental plant and introduced in the 1850s from Japan; it has now become one of the most invasive plants in certain parts of the country and none more so than the South West.


Grown originally for its purple asparagus like spring shoots and ornamental foliage; the plants reach heights of three metres by the end of the summer. Although the reputation for damage has at times been exaggerated, it can push up through asphalt, cracks in concrete, driveways, cavity walls and drains and is therefore a major danger to property and can cause expensive removal costs and repairs.


Property can be directly or indirectly affected (for example if your neighbour has the plant) and mortgage lenders will normally refuse a loan against an affected property unless there is a professional knotweed management plan in place with an insurance-backed guarantee. Sellers are legally required to inform potential purchasers if a property has been or is affected by Japanese knotweed.

Similarly, both a Landlord and Agent must be able to recognise the first sign of this plant to get it treated at the earliest possibility, as the treatment can be quite lengthy. Trying to remove the plant in a DIY manner will normally aggravate the problem and lead to a faster and greater spread!

The common treatment is spraying during the growing season over a two to three year period; in extreme cases it can be physically extracted making sure that ALL of the root is removed. As the treatment is quite costly, it is worth obtaining a Japanese knotweed indemnity policy, these start at less than £100 covering the owner for the cost of treatment, repairs, legal costs (arising from third party claims) and any loss of value should knotweed appear.