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!

THE Programme

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 page.

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 also dead-head (they die once flowered)
  • digging them up, if they are few, young & small

Other Invasives? Japanese Knotweed is also present. Farmers have the expertise to deal with this, although domestic landowners are actively discouraged (but do let us know!). Himalayan Balsam is also widespread, although less problematic, so we may tackle this in the future.

There are several strands to our programme: see Spotting, Spraying, and Supporting.


We have volunteers who walk, cycle or even canoe the river regularly, and record any they see, emailing us at hogweed@elcv.org.uk and/or recording on this map at //tinyurl/THE-RecordIt.

We publish all the sightings on this map at //tinyurl/THE-2019 in enough detail for all landowners to locate (see our Maps page). The Project co-ordinator can also make contact with the responsible landowner.

How do you identify a Giant Hogweed plant? See this NNSS Leaflet or the WildFoodUK website. It's very easy to confuse with Common Hogweed. And how do you identify Japanese Knotweed?


The quickest way to deal with a group of Giant Hogweed is to spray them with a weedkiller like Roundup.

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, and here is his latest newsletter.

Domestic Landowners
Are likely to have smaller infestations, and spraying near water requires 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 nor contractor costs!

The riparian landowners - now numbering around 75, mostly farmers - have all agreed to carry out the control at their own cost. Labour is conservatively estimated at £9000, and chemicals at £800, every year. A total of £100,000 over 10 years, which is an exceptional donation from them.

Bayer UK have already supplied some Roundup to help kick-start our programme, which we distributed at our first public meeting.

The ELC Countryside Service have also shared their data, advice and encouragement.

Will you help £inancially? We can really encourage the farmers by donating at least something to them to help offset their costs. And money for publicity and meetings would help too. Please contact the coordinator James Wyllie or the charity at hogweed@elcv.org.uk

Domestic Treatment

  • 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, dead-head carefully. Although you are probably too late!

Giant hogweed material is controlled waste so, if it is taken off site, should 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 best carry out the work in overcast weather and avoid 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!

Some History

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.


Will you help? We need it!

With spotting, digging, or finance?

Contact the project coordinator James Wyllie or us at hogweed@elcv.org.uk.

Get with the THE programme!

NB: Some images are © Crown Copyright 2009 from http://www.nonnativespecies.org