Information About Japanese Knotweed

Japanese Knotweed (Fallopia Japonica) is a shrub that the Victorians imported into Britain during the nineteenth century for ornamental reasons. Unfortunately when Japanese Knotweed is not in its native environment and subject to its natural predators, it can easily spread and kill off other plant life. It is also extremely difficult to get rid of and consequently has been labelled an Invasive Species by DEFRA (the Department for the Environment) .

While there are a number of Invasive Species in the UK, for example Giant Hogweed and Himalayan Balsam, by far the most prevalent and difficult to eradicate is Japanese Knotweed. Methods to eradicate it are “dig and dump” or chemical treatment. Dig and dump is extremely expensive and consequently WALH use the chemical treatment method. It can however take up to three to four years of regular treatment with chemicals like glyphosate to kill off the plant in its entirety.

Japanese Knotweed grows from approximately March to September each year. During the winter months it is inactive and dies back but it is merely dormant and comes back larger and thicker in the new growing season.

It easily spreads on areas of land that are not well maintained for example railway embankments and canal corridors, it should not however be much of a problem in a domestic setting like a garden. This should especially be the case as tenants agree “to keep their gardens in a neat, rubbish free and tidy condition” when they take up a tenancy with WALH.

Despite this Japanese Knotweed has managed to get a foothold in approximately 250 of our tenants’ gardens and it is becoming an increasing and expensive problem to deal with. In view of this here are a few easy simple steps for tenants to take if they think they have Japanese Knotweed in their garden: -

• Identify that the plant is Japanese Knotweed – a leaflet issued by the Council may be useful in doing this

• Carry out no gardening activity with the plant. Do not cut or trim it as this will cause it to spread and it is illegal to cause it to spread

• Contact your local Area Housing Office or the Contact Centre and ask an Estate Management Officer to visit your garden to confirm that the plant is Japanese Knotweed

• On identification of the Japanese Knotweed the Estate Management Officer will complete an Invasive Species Recording Form and order it to receive chemical treatments by a contractor.

• Please co-operate with the contractor and allow them access to your gardens at all times to carry out the chemical treatments. Failure to do so could mean that the outbreak of Japanese Knotweed will not be eradicated