What next for the plant hunters? Looking around at our garden plants, however, there is a genuine problem. As Bob Brown, of nursery Cotswold Garden Flowers says: "We think we have species, but we really only have clones." All individuals of a clone are identical, which means all plants of a clone have the same strengths and weaknesses. In particular, clones are prone to fungal diseases; if one plant gets infected, they all will, whereas natural populations with wide genetic diversity have varying levels of resistance. In addition, more diversity means more choice: "Look at the summer-flowering perennial Gaura lindheimeri," says Bob. They all used to look the same, white and rather untidy. Now, because of more collections from the wild, we have different colours and forms. Climate change and the unpredictable weather which it brings is a strong argument for increasing the diversity of our garden flora. We need plants which can cope with cold winters and dry summers, but which do not rot off in mild winters or wet summers. Above all we need diversity, so that there is plenty of choice in gardens, nurseries and plant collections; plants to cope with whatever climate change may throw at us. From diversity comes resilience. Above all though, gardeners and the garden industry love new plants. Gardeners" love of, and need for, new plants is not going to go away. Worries over the Rio Convention have actually not prevented plant hunters from doing their best to cater for a passion for novelty. In fact, better travel opportunities have allowed them to thrive and be more adventurous. Plant hunting is now more democratic; no longer does it need wealthy patrons and the right connections, anybody who can afford an air ticket and car hire can now achieve in a week what might have taken a mule train and several months in the 1900s. Unfortunately, one effect of the Rio Convention has been to cast a shadow over the often-friendly relationship that existed between plant hunters and botanical institutions. Botanic gardens were once happy to accept donations of seed from horticultural collectors, but not any more. Some institutions will not even buy plants from nurseries which are known to do wild collecting, for fear of being accused of "bio-piracy." Many in the garden world would be happy with the spirit of the Rio Convention - it seems only right and proper that countries should benefit from their plants, and conservation may benefit as a result. However, there are no mechanisms in place to collect, distribute or transfer either plant material or funds. In fact, the whole issue is a legal loophole. Bleddyn and Sue Wynn-Jones, of Crûg Farm Plants in North Wales, are recognised as Britain's leading plant hunters and they are determined to address the ethical aspects of plant hunting. In Vietnam, for example, they have built up relationships with local botanists. "Most Vietnamese botanists only know their tropical flora," says Bleddyn. We are interested in hardy temperate plants in the mountains in the north, so we can help them with new material. Dan Hinkley, a well-known American plantsman and former owner of the legendary Heronswood Nursery in Seattle, has accompanied the Wynn-Joneses several times and once volunteered the proceeds of open days at his nursery to build new facilities for Hanoi University. "The funds have gone to the right place," says Bleddyn, "they've now got a new herbarium (collection of dried plant material) when they had nothing before." A "fair trade" approach to plant collecting, such as that being pioneered by Crûg Farm Plants, looks like one way to acquire new plants but at the same time to allow countries of origin to benefit. Don't miss A day event at London's Garden Museum 'Plant Hunting in the 21st Century" on October 1, explores these issues; speakers include plant collectors Bleddyn and Sue Wynn-Jones, Roy Lancaster and James Hitchmough. See gardenmuseum.org.uk/page/symposia for more details.