Japanese knotweed rhizome underground system

Japanese knotweed removal techniques

Japanese knotweed can be controlled or removed in several ways.

In the winter, herbicide treatment is not an option as the plant is dormant, with no above ground growth. Japanese knotweed can still be physically removed during this time. Various removal techniques are available, depending on your budget, site conditions and time frame.  

Below we have outlined the different methods we offer. If you would like to discuss one of these Japanese knotweed removal techniques further, please get in touch. Often a combination of methods is required. Our experts will be able to determine the best course of action to suit your situation. 

Dig & Dump
Knotweed infested soils are excavated under the supervision of a specialist. Soils are then loaded into a lorry and taken off site to a registered landfill. This method may be appropriate where small stands of knotweed need to be removed fast. Landfill tax applies to the disposal making it by far the most expensive option. The Environment Agency Code of Practice states that this should considered as the method of last resort, due to the environmental impacts.

Our Xtract™ process was introduced to the market in 2008, providing rapid and reliable removal of Japanese knotweed from construction sites, in a matter of days. The infested soil is excavated and then processed in the Xtract™ machine. The rhizome material is segregated from the soil so that the clean processed soil can be re-used on site. This reduces the financial and environmental cost of consigning vast quantities of infested material to landfill, and avoids the need to import clean fill. 

Root Barrier
A root barrier is considered a control strategy, often used in conjunction with other removal methods and herbicide treatment to minimise the risk of regrowth or encroachment. Vertical root barriers are used at boundaries to prevent encroachment. Horizontal root barriers are used to protect surfaces such as drives, where it has not been possible to remove all Japanese knotweed rhizomes. 

Stockpile & Treat Method
Stockpile & Treat is a cost-effective method for large development sites where space allows for temporary stockpiling. Rhizome within the stockpile is encouraged to grow, and is then treated with herbicide. This method requires large areas of space to be allocated for the stockpile. The treated stockpile material should remain on site, unless it is consigned off site as potentially knotweed infested. 

On Site Burial Method
The method involves the on-site burial of knotweed infested soil, usually contained within a cell lined with proprietary membrane. Its success relies upon the integrity of the cell membrane, which if damaged during or after installation may result in knotweed escape. The method is likely to be less expensive than disposal off site, however it does not remove the problem from the site - it simply contains it. Better alternatives do exist, such as Xtract™.

Share this post