River Tyne Giant Hogweed Eradication (THE) Programme
We plan to eradicate Giant Hogweed
along the entire River Tyne & its tributaries
from the source to the sea
Giant Hogweed represents a serious health hazard for humans. When the clear sap comes into contact with human skin on subsequent exposure to the sun it can cause severe skin burns. Blisters occur within a day or so and dense pigmentation occurs a week later. The skin may remain sensitive to ultraviolet light for years. So however appealing the flowers look don't pick them, and however great a stalk looks as a pea-shooter DON'T!
Giant Hogweed can form dense colonies. Its height and large leaf area forms a dense canopy out-competing natural, native vegetation. Overwinter die-back along riverbanks exposes bare earth resulting in an increased risk of bank erosion. We have enough of that just with fast flowing water!
Biology: Giant Hogweed (see Heracleum_mantegazzianum on Wikipedia) - hereinafter abbreviated to GH- grows for a couple of years before it flowers, usually in July to August, and then sets seed; after which it dies. It only propagates by seed, but a single plant can produce 20,000 seeds. Only a few of these will germinate, and mostly nearby, but some may be swept down river, and thus start a new infestation. For more detail, see the Non-Native Species website
Where are they? Always (well, nearly) on the river bank. We are doing full surveys of the river and all its main tributaries: the Coulston, Birns, Humbie & Keith Waters. See where there all are on our Map.
Who is involved? All the farmers along the river have agreed to be involved (thanks to the hard work and persuasive powers of our coordinator James Wyllie. And all the domestic property owners where GH has been spotted are also on board. It does need everyone along the route, as if we miss even one plant that has gone to seed, we are nearly back where we started.
How Long For? Seeds can lie dormant for up to 5 years, so we will keep this programme going for at least that long.
What Do We Do? We plan to find all the GH plants by the river and treat them. Either by:
- spraying them in Spring, and again as we see them in Summer, before they flower
- if already flowered we can dead-head (they die once flowered)
- digging them up, if they are few, young & small
Other Invasives? Japanese Knotweed is also present, and farmers have the expertise to deal with this. But domestic landowners are actively discouraged. Himalayan Balsam is also widespread, although less problematic, so we may tackle this in the future.
We have volunteers who walk, cycle or even canoe the river regularly, and record any they see, emailing us at firstname.lastname@example.org. We publish all the sightings on this map, in enough detail for all the landowners to locate. The Project co-ordinator can also make contact with the responsible landowner.
The quickest way to deal with a group of GH is to spray them with a weedkiller like Roundup.
Farmers usually have both the equipment, licence and experience to spray, and have kindly volunteered to add GH to their list of targets. Our project coordinator, local farmer James Wyllie, has prepared these notes targeted at all the farmers.
Domestic Landowners are likely to have smaller infestations, and spraying near water require permission, so it is better to dig them up - see below.
What is the cost of this whole programme? It is entirely run by volunteers, so there are no staff or contractor costs! The riparian landowners have all agreed to carry out the control at their own cost of labour and chemical, which is an exceptional donation from them. Bayer UK have agreed to supply some Roundup to start our programme off. The ELC Countryside Service have shared their data, advice and encouragement.
- Pull up young plants by hand when the soil is moist
- For larger plants loosen the roots with a fork then dig out
- If you cannot remove it, sever the root below ground
- If already flowered, dead-head it (which kills it)
- If it has set seed, you are probably too late!
Giant hogweed material is controlled waste so, if it is taken off site, can only be disposed of in licensed landfill sites. To avoid this, dispose of any plant material (dug up or cut down) by composting or burning.
Protect yourself with gloves and long sleeves from any skin contact with the sap, and especially your face, when cutting stems, and carry out control measures in overcast weather avoiding sunny periods. Wash off any sap as soon as possible with plenty of cold water. And don't, like I did, take off your work gloves or jacket and carry it in your hands!
In years past the council countryside team have occasionally organised volunteers to clear a number of young infestations. In 2018 we intensified our efforts and surveyed the route from Haddington to the sea, and dealt with most of the GH we found (see the 2018 layer on the map). Nearly all were killed - either dug up if immature or dead-headed if flowering/seeded. Except in Tyninghame Estate where there were just too many!
And so we realised that with a concerted effort we could completely eliminate GH from the whole river, from source to sea, and the Tyne Giant Hogweed Eradication Programme was begun. The first task was to contact James Wyllie, a retired farmer, who had been the driving force behind successfully clearing GH from the length of the Biel & Whittingehame Waters (see the differences there over the years). Within weeks he had contacted all the farmers along our route and secured their agreement to this programme.