GIVING UP THE WEED
In November 2007, the Esmee Fairbairn Foundation granted funds to the Wye & Usk Foundation for an invasive weeds eradication project in the Wye and Usk catchments. The project will continue over three years and is supported by the Environment Agency Wales, Countryside Council for Wales, Natural England and Keep Wales Tidy.
Our catchments are under a very considerable threat from at least three species of invading weed. Rivers and streams are the ideal vector for carrying seeds and plants downstream. They can, however invade upstream via a number of means. Our concern is for the loss of biodiversity and, since these plants smother the native species that armour the river banks, the increased erosion that will occur.
The invading trio of species includes:
Giant Hogweed - Heracleum mantegazzianum
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Perennial – grows 5 -7m.
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Member of parsley family.
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Arrived in UK 1893 from Caucasus.
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Sap causes serious rashes when skin exposed to sunlight. Can cause blindness.
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Can be controlled by spraying, grazing, cutting or digging- up.
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Spraying with Glyphosphate (Round Up) is a successful treatment.
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Spread by rivers and seeds last 3 or more years.
Japanese Knotweed - Fallopia japonica
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Arrived in UK (South Wales) late 19th century.
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2 – 3m height but spreads 7m horizontally.
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Perennial Rhizome.
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Edible (the early shoots!).
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Female only in UK but can Hybridise with Himalayan Knotweed.
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Can be spread via small cut pieces.
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Estimated to cost £1.56 billion to eradicate in UK (2007).
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Significant issue for developers (eg Olympic grounds).
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Can be sprayed with round up but can prove resistant.
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Can hybridise with Himalayan Knotweed which has male flowers.
Himalayan balsam - Impatiens glandulifera
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Arrived UK in 1839.
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Annual - grows 2m typically on river banks.
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Suffocates native plants if unchecked.
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Approx 800 seeds can last 2 years.
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Can be treated by spraying, pulling or cutting.
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Causes increased erosion to river banks.
Giving up the Weed: How the project will operate.
The grant will be used to pay for:
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Plotting of all Invasive weeds on a database as currently known and received from reports (years 1-3).
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Training five staff in the techniques of spraying (year 1).
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Eradicating Giant Hogweed in the Wye (Glasbury downstream for over 80km in the spring (Years 1-3).
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Eradicating all Himalayan Knotweed in both catchments (year 1).
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Eradicating all Japanese Knotweed starting from extremities of the Usk and Wye (years 1-3).
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Developing volunteer networks to manage Himalayan balsam.
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Study the effects of fencing out buffer strips and the effect on invasive weeds.
A Foundation spraying team tackling Giant Hogweed
Dying Giant Hogweed after spraying
Budget:
The Esmee Fairbairn Foundation grant of £94,000 over three years will be added to contributions from WUF, Environment Agency Wales, Countryside Council for Wales and Natural England to give a total budget of just under £150,000.
Progress to date:
2008 The teams were trained in spraying techniques and between April and early June 37km of double bank Wye was sprayed to eradicate Giant hogweed. In late summer, 36 sites (4 hectares) of Japanese Knotweed were treated, along with two Himalayan Knotweed sites. We prioritised sites where spread was likely - where it was being cut or could be washed into the river.
2009 Spring: 42 km of the main stem of the Wye was sprayed recovering some of 2008s work. Notable reduction in plant numbers. Small number og GH sprayed on Monnow. Autumn spraying of Japanese Knotweed. Trial Himalayan balsam pulling on Llynfi Dulas and Main Wye.
Total to date: 343 stands over 42km of the Wye (double bank) has been sprayed to eradicate Giant hogweed (more stands over smaller length than in 2008). 3 stands (0.02 ha) of Himalayan knotweed (HK). 247 stands of Japanese knotweed (JK).
2010 The project has taken on overall management of the Usk Giant Hogweed. 54km of main stem Wye sprayed or resprayed with considerable reduction in plant numbers. Usk GH sprayed between Glanusk and Trostrey. Knotweed spraying planned for autumn and trials of Balsam eradication including pulling, spraying and cutting continuing.
How you can help
1. Please notify us of any Giant Hogweed or Japanese Knotweed on the Wye or Usk by email on weeds@wyeuskfoundation.org
2. Volunteering to assist with our balsam pulling programme
3. Advising others of the Dangers of Giant Hogweed
4. Advising others not to cut or dig Japanese Knotweed – it can be spread easily this way.
