Giant Hogweed hits the headlines every summer as members of the public are injured by its poisonous sap, which can cause painful blisters and severe skin irritation. But the weed is also an invasive plant, which has a serious impact on the biodiversity of the riparian and aquatic environment.
This year, farmers and a local community in Scotland have come together in a project to tackle Giant Hogweed, using equipment and labour supplied free of charge by local farmers.
Managed by the East Lothian Countryside Volunteers (ELCV), the project is based at Haddington, East Lothian, at the centre of an area through which the River Tyne flows, with Giant Hogweed growing on its banks.
Local farmers have joined forces to combat the weed, using the highly effective glyphosate herbicide Roundup, some of which has been donated to the project by global manufacturer Bayer.
Volunteers pin point affected areas
Spraying started in March 2019, with 50 qualified farmer operators using knapsack sprayers to apply Roundup alongside the river, with help from an online dynamic map created by the ELCV, which pinpoints the worst affected areas using reports from volunteer spotters, and allows them to be ticked off as they are treated.
Local farmer James Wyllie was asked to co-ordinate the initiative, having previously led a campaign to control Giant Hogweed on an eight mile stretch of the Biel and Whittingehame Water in East Lothian.
He explains: “The original proposal was for 10 miles of the River Tyne, but there was such a high level of support from the landowners to participate in a project where all the riparian owners were acting together that it has expanded way beyond the original plan. It now covers about 48 miles of the River Tyne from A68 to the sea and including two major tributaries, Birns Water and Colstoun Water in an area with around 75 riparian landowners participating.”
Other invasive weeds also targeted
While the main focus is on Giant Hogweed, Japanese Knotweed and Himalayan Balsam are also being targeted by operators as they spray.
Mr Wyllie adds: “It’s going to take five years to see a real difference, due to Hogweed seeds which are embedded in the soil and will germinate in future years. We aim that no plant should be allowed to flower, as each can produce 10,000 seeds, and any flower heads that are produced need to be removed and disposed of safely.”
“The open access dynamic map is key because farmers can see exactly where plants have been observed along the river and when overlayed on a satellite map helps to pinpoint areas to inspect. Later in the season where there are no flowering plants left it is marked with a green tick.”
In small areas of non-agricultural land, removal of any odd Giant Hogweed plants are tackled by the ELCV volunteers to ensure that there are no gaps.
Bayer’s Roundup Technical Development Manager Barrie Hunt says: “This is a unique project in that it attempts to treat an almost complete river catchment area, which gives the best chance of tackling the weed. Where only part of the catchment is treated, there is always the risk of plant material being washed down river and Giant Hogweed re-establishing itself. We have been pleased to work with the ELCV and Mr Wyllie on such a worthwhile operation.”
Sponsorship from Bayer and Scottish Natural Heritage
As the growing season drew to a close at the end of July, Mr Wyllie commented that he has been overwhelmed with the positive response to the project. “Every farmer approached has offered to support the work – labour contributed by farmers free of charge will be worth around £100,000 over a 10 year period – and we are very grateful for the sponsorship from Bayer and backing from Scottish Natural Heritage.”
He added that Roundup has been key to the success of the project.
“I’ve used it for 25 years and it is one of very few products that is approved for aquatic use; there are no ground residues and it works by contact onto the leaves only. It’s also very effective on Japanese Knotweed and Himalayan Balsam.”
“This is a long term project on a large scale, which demonstrates East Lothian farmers and the local community working together to achieve a common goal.”