Japanese Knotweed Fallopia japonica was first introduced to Britain by the Victorians as an ornamental plant – and was actually awarded a gold medal at a prestigious flower show. It is referred to under its previous name of Polygonum cuspidatum in ‘The English Flower Garden’ by John Murray. In the 1907 edition it is cited as “easier to plant than to get rid of in the garden“.
In its native countries of Japan, North China, Korea and Taiwan, the weed presents nowhere near the problem it now poses across Europe, America and New Zealand. With its natural habitat being on the slopes of volcanoes, it is no surprise that the less harsh and more fertile environment of Britain has allowed this plant to flourish to extreme proportions. Furthermore, outside of Asia, the plant has no natural biological enemies to check its spread. In Japan, for example, at least 30 species of insect and 6 species of fungi live on the plant.
This plant is perennial and extremely invasive. Japanese Knotweed does not spread from seeds in the UK. It is spread when small pieces of the plant or rhizomes (underground root-like stems) are broken off. One piece of rhizome or plant the size of a fingernail can produce a new plant. It soon overruns riverbanks, railway embankments, road verges, gardens and hedgerows, threatening the survival of other native plant species and in turn insects and other animal species.
Japanese Knotweed is so invasive and destructive that in some areas home buyers are being denied a mortgage by banks and building sites because the property they are trying to purchase has been affected: capable of pushing through concrete, the plant can pose a serious risk to the structure and fabric of a building.
In 2004, a DEFRA review of non-native species policy stated that a conservative estimate for the costs involved in eradication would be £1.56bn. The aggressive spread of the plant following its first escapes into the wild in the 19th Century resulted in it occurring in most parts of the UK (except Orkney) and eventually being listed in the Wildlife and Countryside Act 1981 as a pest species. All parts of the plant are considered as controlled waste under the Waste Regulations.
Countryside and wildlife act 1981
“If any person plants or other wise causes to grow in the wild any plant which is included in part 2 of schedule 9, they shall be found guilty of offence. Japanese Knotweed is included in the schedule of plants. Any person convicted under this act could be liable to a fine of £5,000 and / or 6 months in prison or 2 years in prison and unlimited fines on indictment.
Is it illegal to have Knotweed on your land or property?
It is not illegal to have Japanese Knotweed on your land but you must take reasonable action / steps to prevent it spreading to your neighbours land. If it does spread your neighbour may be able to sue you in the civil courts. Responsibility to control rests with the owner of the land. Local authorities etc do not have to control it on behalf of other landowners. Actions in civil courts can be expensive and risky. The best course of action is to consult with the owner and point out his obligations first.
Environmental Protection Act 1990
Japanese Knotweed is classed as ‘controlled waste’ and as such must be disposed of safely at a licensed landfill site according to the Environmental Protection Act (Duty of Care) Regulations 1991. Soil containing rhizome material can be regarded as contaminated and, if taken off a site, must be disposed of at a suitably licensed landfill site and buried to a depth of at least 5 m. – See more at: http://www.devon.gov.uk/index/environmentplanning/natural_environment/biodiversity/japanese_knotweed/whats_the_problem/jk_and_the_law.htm#sthash.XoVrqKiX.dpuf
Hazardous waste regulations 2005
Only applicable if Japanese Knotweed has been treated with certain residual herbicides. Again failure to comply with the act could lead to prosecution.