Knotweed Information

Japanese Knotweed is without doubt among the biggest challenges for today’s construction industry. As it is a highly invasive weed, which can spread very quickly from only a small fragment, and cause extensive damage to property and displace native species of flora. In addition the plant can regenerate from rhizome fragments as small as 0.7gram and can remain dormant in the soil for over four years making a professional and scientific approach to its eradication vital if 100% success is to be guaranteed.                 

Japanese Knotweed is proscribed under the Wildlife and Countryside Act 1981, making it an offence to allow the plant to spread. All parts of the plant, and any soil contaminated with the rhizome, are classified as “controlled waste” requiring all the “duty of care” requirements under the Environmental Protection Act 1990 to be met. See our JK & the Law page.Most guidelines suggest a program of eradication works lasting three years. IVM feel that it is unacceptable for development companies, builders and the like to have to wait this long.

Invasive Vegetation Management developed the 'FAST' system for eradicating Japanese Knotweed. It uses a range of application techniques developed which significantly increases the effectiveness of a standard herbicidal treatment method, to the extent that complete eradication can usually be achieved within one growing season of the treatment program. When used alongside IVM's tailor-made site solution, they make a formidable partnership! Sometimes even allowing the construction program to continue un-affected.

The cost of the FAST system is approximately 15-20% of dig and dump. Its main application is for development sites, where there is a timeframe of around eight months or more prior to construction activity and/or where circumstances prevent an effective dig and dump strategy. The FAST system also has additional environmental benefits in that typically the eradication process results in significantly lower rates of herbicide application when compared with the standard herbicide treatment methodology. If Japanese knotweed is left un-treated it can damage;

• Pavements, Roads and Car Parks
• Retaining Wall Structures
• Building Foundations
• Flood Defence Systems
• Archaeological Sites

In addition knotweed can;

• Reduce Land Values
• Delay Construction Projects
• Reduce Biodiversity Through Out-Shading Vegetation
• Restrict Access to Riverbanks for Anglers, Bank Inspection and Amenity Use
• Reduce the Visibility of Roads and Railways

For more information on our treatment methods and the company contact IVM