International Rhododendron experts meet in Edinburgh

Rhododendron Kanehirae


     International Rhododendron experts meet in Edinburgh

As we celebrate the arrival of spring and look forward to the flowering of ever-popular rhododendrons and azaleas, the Royal Botanic Garden Edinburgh plays host to a group of international experts meeting to develop a plan to save threatened Rhododendron species from extinction in the wild. Although common in cultivation, research by Botanic Gardens Conservation International (BGCI) and the Royal Botanic Garden Edinburgh (RBGE) published in 2011[1] showed that a quarter of the more than 1,000 known species of Rhododendron are under threat in their native habitats. Indeed, one particular species (Rhododendron kanehirae) would be extinct but for collections in botanic gardens such as RBGE.

Famous for their flowers, Rhododendrons (including azaleas) have long drawn plant hunters to their centres of diversity in the Himalayas and mountains of Southeast Asia.  In their native habitats, Rhododendrons are valued for their medicinal properties, and in some communities they have a wide range of other uses, including firewood, timber, teas, jams, narcotics and also as a source of insecticide.  Rhododendrons grow in areas of high rainfall and high humidity on acidic soils; conditions under which few plants would survive. They stabilize slopes and protect watersheds, notably in the Himalayas where so many of Asia’s major rivers start.

BGCI’s 2011 report highlighted the urgent need for conservation of 75 of the most threatened Rhododendrons - species that were considered to be on the verge of extinction in the wild.  Furthermore, the internationally adopted Global Strategy for Plant Conservation, calls for 75 per cent of all threatened plants to be conserved in ‘ex situ’ collections (e.g. botanic gardens) by 2020. In the case of Rhododendrons this equates to 238 species. 

In 2012, BGCI carried out a survey to see how many of the threatened Rhododendrons were already in the collections of botanic gardens and arboreta around the world. Worryingly, only 48 such species were identified.  This means that many of the Critically Endangered and Endangered species are currently not known in cultivation and therefore at great risk of extinction if the threats that they are facing in the wild are not addressed.

Armed with background information on which species are most at risk in the wild, and which are not already in conservation programmes, the experts meeting in Edinburgh his week will be working to develop a coordinated action plan to ensure the future of this family of distinctive and beloved plants.

Sara Oldfield, Secretary General of Botanic Gardens Conservation International said: “Rhododendrons will soon be in full bloom in our gardens. In their natural habitats these same species are in trouble. Horticultural skills are urgently needed to restore endangered Rhododendron species in China and other parts of Asia where they are important components of mountain ecosystems. BGCI is committed to help save these beautiful plants from extinction.”

Ian WJ Sinclair, President of the Rhododendron Species Conservation Group commented:“It is encouraging to see so many key authorities on rhododendrons come together under one  roof to discuss the importance of this issue. The aim of the weekend is to agree priorities and establish a plan of action. By working together it should be possible to pave the way for more effective international communication in the sourcing of important research and conservation materials. I have no doubt that this conference has the potential to make a significant contribution in saving the species at risk in their natural habitat and that the creation, already underway, of accurately named GPS records of known wild origin rhododendrons in cultivation also has an important role. Already, the Rhododendron Species Conservation Group – in association with BG Base, biological collections search engine, developed by RBGE and its partners - has records of 98 Scottish gardens with roles to play in this initiative”.

John M. Hammond, Conference Manager & Secretary of the Rhododendron Species Conservation Group noted: “Without any doubt, 'The Red List of Rhododendrons' is a stunning taxonomic and scientific assessment of how man, nature and environmental factors can each adversely impact on the natural habitat of around 1000 species across the globe.  Time is of the essence, and the concerns raised by this publication are beyond the sphere of control of taxonomists and scientists to resolve, added to which some species are also becoming rare in cultivation.  In seeking a way forward, this conference aims to assess and recommend what opportunities exist for implementing a practical approach through the involvement of curators, head gardeners, horticulturalists, nurserymen and enthusiasts from around the world, who have the knowledge and expertise to work together to propagate, raise and cultivate plant material to establish conservation collections in botanic gardens, arboreta, parks and woodland gardens where climatic, geographic and environmental conditions enable the various types of species to flourish.  In this way we can work together to secure these plants for future generations to enjoy.”  


The Royal Botanic Garden Edinburgh is a charity (registration number SC007983)