In an effort to tackle invasive Japanese knotweed on their M25 junction 10 upgrade, National Highways has enlisted the help of some four-legged friends with a nose for justice.
Known for its aggressive growth and resilience, Japanese knotweed can shoot to over 2.1m high, supressing all other plant growth.
National Highways called on three highly trained, tail-wagging sniffer dogs – Fenix the Dutch Shepherd, and Spaniels Nica and Nettle – to root out the havoc-wreaking weed and to prevent it spreading.
The specially trained dogs help by detecting the rhizomes, the underground parts of the plant such as roots, bulbs, and shoots, which when removed prevents any spread or re-growth.
Explaining the unique approach, Pippa Jordan, said: – “Environment Lead on National Highways M25 J10 improvement scheme, said: “Conservation plays an important role in our construction projects. Before we start, we create a map of the area which shows nearby plant species allowing us to tackle any invasive species growing on the construction site.
“In this case, we decided to put our paws on the pavement and take a unique approach to tackling the Japanese knotweed. These sniffer dogs are not only adorable, but also incredibly skilled at detecting the presence of unwanted plants, especially those not readily visible.”
If not found and dealt with, the plant can cause serious problems to buildings and structures. It’s also an offence under the Wildlife and Countryside Act 1981, to allow these invasive plant species to spread in the wild, which is why National Highways called in the canine specialists to help solve the issue.
When the dogs detect Japanese knotweed, they freeze to alert their handler. This allows National Highways to take swift action to eradicate the plant and prevent further spread.
Kat Janczur – owner and handler at Canine Detection Solutions – said: “"The dogs have got the most amazing sense of smell, and they can pick up the scent that Japanese knotweed rhizome gives off into the soil. They're amazing animals and a great tool in efforts to prevent the spread of these invasive plants on and around the site.”
Kat and the sniffer dogs started on the southern verge of the M25 site with Fenix, the Dutch Shepherd, before back arrived in the form of Nica, a springer spaniel. Each dog can only be worked for 30mins before requiring rest for at least the same time to keep efficiency levels up.
On the second day, Kat and her dog-tectives investigated the A3 northbound verge before heading to Seven Hills Road. This time Fenix was assisted by a young cocker spaniel called Nettle.
All dogs successfully found several areas where rhizomes were located underground. These areas would have been missed until the next season that the plant would have sprouted. Japanese knotweed can lay dormant for up to 20 years, so using detection dogs allowed for a full site clear, regardless of the state of the plant.