Our Work

Our clients hire us because of our sector expertise and our research knowledge. Here are a few case studies of how we’ve helped our clients with Japanese Knotweed and other invasive weeds.

London Overground, Transport for London

Description of works:
The discovery of Japanese knotweed growing vigorously on a site in West Hampstead that London Overground needed to use to widen an existing platform was a major issue. TCM were brought in to solve the problem. Once authorisation was gained from the housing development next door to work from their site, TCM began to ‘dig and dump’. The soil had to be dug out and taken off site as the quickest and only real option available. The whole project took 16 days. The rhizomes were very deep so we excavated 4 meters down using 108 of 20 tonne Lorries to take away the contaminated soil to landfill.

Problems TCM overcame:
It was not an easy job. Dean Forde, managing the project, could see a number of concerns that needed to be taken into consideration. “The area we would be working in had overhead power lines, it was on a bank made up of rubble, wood and metal and there were the overriding concerns that it was a busy commuter train station next to a housing development in full operational swing.” Some of the Japanese knotweed was very close to the live track a procession order was issued on the track for one day. A Sunday was chosen when it was least disruptive to commuter trains but the pressure was really on to get it done in a day which we successfully achieved. With more Japanese knotweed on a bank, we were working very close to the overhead power lines so we used a height and sloo restrictor on the excavator.

TCM were able to issue a warranty covering the entire site in June 2014.

New Zealand Pygmyweed (Crassula Helmsii)

New Zealand Pygmyweed is a fast and thick growing aquatic weed. A dense mat of vegetation covers water and surrounding marshland, restricting sunlight and warmth to surrounding plants and wildlife. It is difficult to target because typical herbicidal treatment can contaminate the water source and be harmful to local wildlife.

TCM’s Holistic Integrated Technology (HIT) is approved for use on aquatic weeds like New Zealand Pygmyweed as it minimises the use of herbicide, in accordance with the Environment Agency’s guidelines.

In a case study where a protected species was present, TCM R&D worked closely with local ecologists to protect the local biodiversity.

Description of works:
The site had been earmarked for development and was prone to floods so the works had to be carried out as quickly as possible, before the weather got too bad.

Great Crested Newts had been found on the site by ecologists and TRAP fencing had been fitted all around to protect the species. Before the works began, the newts had to be relocated to a safe habitat and the fencing removed.

An excavator carried out a 300mm scrape and stockpiled elsewhere on the site. TRAP fencing was fitted around the original area and the stockpile so that the newts would not have contact. Once the Pygmyweed had dried out in the stockpile it was transported to an approved landfill site.

These works were completed by our experienced operatives in just five working days.

The Borders to Edinburgh - Cell burial

Description of works:
Japanese knotweed and Giant Hogweed was excavated from the site of the new railway line and placed in a cell some seven miles away from the excavation site

VHE Construction (Land Remediation)

Description of works:
Mechanical screening of 6,000 m³ hazardous material which contained Japanese knotweed. TCM worked closely with VHE Construction to remove Japanese knotweed from hazardous material prior to soil washing treatment. By closely monitoring excavation, TCM were able to significantly reduce the volume excavated by approximately 40%, offering a more sustainable and cost effective approach to the problem when compared to excavation and removal to landfill. The soil screening was supervised and undertaken by fully qualified and in-house trained staff.

Problems TCM overcame:
Due to the presence of a variety of services, including a substantial electricity substation and overhead power lines, significant health and safety provisions were implemented. As the site is adjacent to the River Clyde, substantial infestations on adjacent land and significant infestations of giant hogweed, a 2 year herbicidal treatment programme using TCM’s HIT® methodology is being undertaken.

This all-encompassing approach will allow TCM to offer a bespoke 10 year warranty which will cover the entire site.






Sq Mt Cleared

  • We are experts in removing japanese knotweed
    through proven scientific methods.

    We are experts in removing japanese knotweed through proven scientific methods.