From an exotic import to  ‘aggressive’ plant species 

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Wealthy Victorians grew the garish rhododendron ponticum ‘to ornament our houses in the Spring,’ as a magazine of the time put it. The first British catalogue listing in 1793 for the exotic import from Spain and Portugal was an astronomical seven shillings and sixpence for a single plant (or over £52 nowadays). Some 200 years later, attitudes have changed. 

“It’s the most aggressive and virulent species of rhododendron we know of,” said ecologist Nabil Abbas from Sheffield and Rotherham Wildlife Trust, after helping to rip out 200 metres of escaped Victorian household ornaments. 
“It grows very rapidly, it sends out tiny airborne seeds over long distances, it creates dense thickets that shade out ground flora, it releases chemicals that inhibit other plants, and it’s toxic to livestock. It’s not got a lot going for it really.” 
Land managers like the Wildlife Trust are keen to reduce rhododendron in many areas of Sheffield and the Peak District, where it was also actively planted as cover for game birds. The National Trust’s long term plan for the High Peak is to completely eradicate the plant from moorland areas.
“If there’s no management of rhododendron it really romps away on acidic peaty soils,” said National Trust Countryside Manager for the Peak District Ted Talbot. “You can watch a stretch of moors over ten years and see rhododendrons marching across like a gang of triffids.”
He added that there’s a place for rhododendron in environments associated with estates like Longshaw or Chatsworth where the species is part of the historical planted landscape. 
“The flowers are lovely and children enjoy the network of dens under the bushes, but the species needs to be removed elsewhere to protect the wider moorland and woodland habitats.”
High above the Strines reservoir, Nabil and team had been clearing a stream of rhododendron bushes which had shaded out everything except dry earth gradually eroding into the Strines and the river Don. 
“In a healthy upland clough you get rushes and sphagnum moss and other plants that hold back the water and stop erosion and generally slow the flow down into the city,” said Nabil. “But if you’ve got rhododendron with bare soil underneath, the water just rushes straight through.” 
Part of the Sheffield and Rotherham Wildlife Trust’s four year Lakeland Landscape Partnership Project in the Outdoor City’s north west countryside is to use ‘natural flood management’ to reduce the risk of flooding. 
Taking out invasive species like rhododendron on water courses allows plants native to Sheffield’s moorland fringes to return and hold back and slow water heading to the Don after heavy rainfall. Moss and rushes also improve water quality by reducing acidity and filtering out peat and soil fragments. 
Nabil Abbas said that climate change will increase extreme wet and dry weather which makes natural flood management even more important to reduce the flow of water into cities. 
The work will also benefit wildlife like native birds and animals who get little benefit from the Victorians’ favourite floral bush. 
But organisations like the Wildlife Trust and the National Trust need volunteers to help fight back against wandering rhododendron.
National Trust ranger Myles Brazil has seen the difference clearance work makes. “You speak to people who remember an area of land that was just a dark green mass of rhododendron, but now there’s heather, bilberries and young trees coming through along with wildlife like snipe and curlew. But volunteers are crucial. With a team of a dozen or so people you can clear in two hours what might take you two days otherwise.”
Last week’s work near Jacob’s Plantation at Strines was carried out by enthusiastic hard core weeders from the Environment Agency who work on natural flood management as their office job. 
“It’s quite heavy work but it’s nice to see the impact of what you’ve done, and the difference partners like the Wildlife Trust are making to restore the natural processes here in the uplands,” said Jenny Barlow from the Environment Agency. “And we actually feel lucky to be able to spend a day out here where it’s so beautiful.” 
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