When carrying out a permanent burial of Japanese knotweed on site, Japanese Knotweed Expert will follow the procedure below:

Firstly, we will sift the soil and the main stand and rhizomes removed. From this, we will then put the soil into a dumper and the soil is spread back into the hole that has been excavated. Afterwards, we will re-check the soil and any rhizomes that are missed will be removed. The root barrier should be UV and animal resistant. Also, they are guaranteed for 50 years. The guarantee needs to be this long because the Japanese knotweed rhizome can remain inactive for over 20 years. Ideally, the barrier would not contain any joins and would be one large sheet for the entire area.

Japanese knotweed can damage concrete. So, it will easily break through seams if they are not properly jointed. Therefore, this means a competent individual should have to join the two root barriers if required. If we cannot bury the contaminated soil at a depth of 5 metres, it can be buried with just 2 metres of uncontaminated soil on top of it. However, the mound of contaminated soil must be totally encapsulated within the root barrier membranes.

Sand or identifying tape should be put on top of the membrane to make it easily identifiable if anyone digs in that area in the future. Ideally, we would bury it where there is landscaping work on the site and any trees are planted above the stockpiled Japanese knotweed.