Chemical Control (Herbicides)
Foliar application: This type of treatment solution is usually applied with a sprayer such as a knapsack sprayer. It is an efficient way to treat large monocultures of invasive plants, or to spot-treat individual plants that are difficult to remove mechanically such as Japanese knotweed. For deep rooted species, such as Japanese knotweed, regrowth will occur in subsequent years, all be it much less vigorously, which will require follow up treatment at the appropriate time of year. Spot treatment will be required each year until no regrowth is observed.
The stem injection method or solution is sometimes used for Japanese knotweed control. This treatment requires a higher concentration of the active ingredient than is used in foliar applications. In addition many of the recommended herbicides for foliar application are not approved for application by this method. It involves the use of a specialist herbicide injection tool whereby the injection tool injects the herbicide directly into each of the canes approximately 20-30cms from the base of each cane (between the 1st and 2nd nodule).
Subsequently approximately 10 mls of herbicide mix is injected into each cane at a ratio of 5:1 through the use of a specialist stem injection tool. The application of glyphosate based products, are most effective when applied in the early Autumn (Mid to Late Sept). Regrowth will occur in subsequent years, all be it much less vigorously, which will require follow up treatment at the appropriate time of year. Spot treatment will be required each year until no regrowth is observed.
Excavation and Encapsulation
This method involves mechanically excavating contaminated material and burying on site at a depth of 5m wrapped in a protective membrane. This method and treatment solution can only be used if the site is a suitable size.
The contaminated soil is put through a onsite screening machine where the Roots (Rhizomes) are separated from the soil. The Rhizomes are then removed and disposed of at a Licensed Landfill site. The soil can then be re-used on site.
Excavation and Removal (Dig & Dump)
The Contaminated soil must be excavated to a depth of 3m and extend to 7m from any Japanese Knotweed located above the ground. The Soil will then be loaded onto Lorries and securely sheeted , it will then be transported to a Licensed Landfill site. The Soil is classed as Controlled waste and can only be removed by a Licensed waste carrier.