Japanese Knotweed Control And Eradication

Japanese knotweed is a highly invasive plant that can cause extensivedamage to property where it is growing.

Where this nasty invasive plant is on development sites, it can delaythe construction process by several years and indirectly costing a lot of moneyto the land owner and the developer. The invasive weed has an extensive rhizomesystem extending some seven meters laterally from the visible Japanese knotweedplant and up to three meters deep from the crown. A spectacular spread ofknotweed will occur by disturbing the soil containing the annoying plant, asfragments of rhizome weighing less than one gram will regenerate into a newplant infestation, growing to a height of around three meters in one growing season.Consequently, Japanese knotweed infestations are increasingly found throughoutthe United Kingdom, Europeand America, and, as theinvasive weed does not have any natural predators, the problem is escalating tothe extent that DEFRA now estimate the cost of Japanese knotweed eradicationwithin the United Kingdomto be between one and a half and two point six billion pounds.

The invasive weed is listed under Schedule 9 of the Wildlife andCountryside Act 1981, making it an offence to cause the knotweed or allow it tospread in the wild.

All parts of this invasive plant, and any soil contaminated with its rhizome,are classified as Japanese knotweed "controlled waste"� requiring all theJapanese knotweed "duty of care"� requirements under the EnvironmentalProtection Act 1990.

The plant has no respect for property boundaries and it can cause manyneighbour disputes.

Japanese knotweed solutions to eradicate the plant can involveneighbours thereby causing differences of opinion with its control.  Japanese knotweed is regarded as more seriousthan a nuisance and any invasive plant affecting boundaries should bedestroyed. Often the control and eradication of the plant in this instance cancause complications. Insisting on Japanese knotweed removal or Japaneseknotweed eradication is a common law right but expensive to instigate.

The Environment Agency's Knotweed Code of Practice "Managing JapaneseKnotweed on Development Sites"� is a useful reference guide andoutlines the various options for Japanese knotweed removal.

Due to the legislative regime of Japanese knotweed and highly invasivenature of the plant, ignoring Japanese knotweed is not an option.

Careful management of Japanese knotweed infested material is required toprevent its spreading. The volume of Japanese knotweed infested material can besurprisingly large due the extent of horizontal and vertical penetration of therhizome system into the soil.

Japanese knotweed treatment options can often fall into two categorieswith Japanese knotweed removal - in situ treatment or physical removal of allviable Japanese knotweed rhizomes.