Snowdrops signalling the first signs of Spring “I’ve been exhibiting at Chelsea for more than 25 years and have seen so many nurseries disappear and with them collections that include carnations, violas, alpines, conifers, sweet peas – all gone.”Celebrity gardener Alan Titchmarsh is working with the RHS on a campaign urging gardeners to buy from specialist UK growers. He is opening the Welcome Building at RHS Wisley on the 10th June, which is dedicated to plants from specialist nurseries and will have a dedicated space the size of four Olympic swimming pools for rare varities. A horticulturalist at RHS WisleyCredit:Oliver Dixon / RHS “Many British growers are constantly trying to create the best of their variety be it the tastiest, hardiest, most colourful, prettiest etc. so there would be no ‘improved’ versions of our favourite plants coming in anymore – improvements would stop and therefore we would lose resilience. As the climate changes this could become a big problem as we wouldn’t be creating new plants that can cope with extended droughts for example or winter floods.”Exhibitors at Chelsea have warned of the decline of British nurseries. The “Queen of Herbs” Jekka McVicar said: “UK nurseries are dying out and this is extremely sad – if they go, we lose the rich variety of plants in our gardens, we lose the skills and knowledge you can’t find anywhere else, we lose collections. Like endangered animals, we’re at risk of extinction, and if this happened it would be devastating. Mr Titchmarsh said: “These plant specialists lovingly grow the rarest, most unusual and beautiful varieties in the world, which thrive in UK gardens because they’re so used to our climate.“I promise to help Greening Great Britain by continuing to promote and buy from specialist UK growers. If the UK’s army of 27 million gardeners were to do the same, we would be protecting the UK from pests and diseases coming in from abroad; helping pollinators which need a diverse range of plants in order to survive; and supporting this vital industry that is worth more than £24 billion to the UK economy.” A horticulturalist at RHS Wisley Snowdrops signalling the first signs of Spring British flower varieties including roses and snowdrops are at risk of dying out, the Royal Horticultural Society has warned, as specialist gardeners are a dying breed because young people don’t want to work in horticulture.While Britain is known for its beautiful and unique breeds of flowers, showcased every year at Chelsea Flower Show, this legacy is at risk as there are 23 per cent fewer specialist growers now than there were in 2000.The rich varieties of plants in our gardens are largely down to these nurseries, which hold vast collections and grow the most unusual and rare varieties on earth. If they were to go, then we would lose this diversity which is vital for pollinators, and we would also lose breeding strains and vast amounts of knowledge that can never be replaced. As the experts retire, millennials are not replacing them as many do not want to work in horticulture. Additionally, small businesses are having to compete with superstores that ship masses of the most popular varieties over to the UK from countries such as Holland.The RHS chief of horticulture, Tim Upson, explained: “It’s the rare and unusual varieties that are at risk in the most immediate sense. If you take snowdrops for example, there are currently several hundred varieties, this would be reduced to a handful. The same goes for all our favourites, including roses and a key point is that we would have no new varieties introduced here in the UK. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily  Front Page newsletter and new  audio briefings.