The Occasional Gardener: The Chelsea Flower Show in London is the place to find out what's cutting-edge in gardens this summer'
I had no idea that fashions in plants change as regularly as skirt lengths until I overheard a conversation about the unfashionability of geraniums.
I've obviously made a huge faux pas by putting a clump of pink geraniums outside my front door (very handy for dead-heading) - but I'm not going to pull it up because the flowers are pretty and because, as we know from flared jeans and platform shoes, even the most unlikely trends come back eventually.
But how do ordinary gardeners find out about the latest plant and garden fashions and innovations? An annual style guide is the RHS Chelsea Flower Show. Since 1913, the show gardens have mirrored the enthusiasms of garden designers - going from the topiary and bonsai of the early years, the rock garden craze of the 1940s, and the cottage gardens of the 1980s through to today's sculptural gardens which use materials such as glass and steel.
Colour is just as important in gardening as in clothing. Last year's Chelsea was dominated by the colour purple - lavenders and aliums seemed to be everywhere - but this year, it looks like green, or even black, will be the new purple. One show garden featuring black is the Salvation Army Garden, which takes the visitor on a journey of hope and transformation, from darkness to light; from a black lawn through to gold, silver and white planting.
Green is used by designers to highlight shapes and textures of plants, from a carpet bedding of cacti and succulents in "Think . . ." to Diarmuid Gavin's "Colourful Suburban Eden" which was apparently inspired by Ireland and, you've guessed it, has more than 40 shades of green. Gavin will also build his signature metal structures, this time in the form of a curved pagoda and a "wave" of spheres on steel posts.
But we don't all want steel in our gardens; several Chelsea gardens should provide ideas for anyone who wants to attract wildlife and generally improve the environment. The "biodiversity" garden created by a London school includes a "bug hotel", a bat house, a hedgehog home and a solar-powered water feature (which can also be powered by nearby exercise bikes). While the London rooftop garden shows that you don't need to live on the ground to do your bit for the environment - inspired by Westminster City Council's campaign to encourage rooftop gardens, the "Reflective Garden" re-uses rainwater and air-conditioning water and features recycled traffic signs.
Fashion in other areas of life is reflected in the gardens at Chelsea. Lovers of all things magical and mystical - from Harry Potter to Lord of the Rings - will enjoy "From Merlin to Medicine", a garden inspired by King Arthur which celebrates the mystical and medicinal properties of plants and features a spectacular waterfall, a cave and Merlin's tower, surrounded by a fence of swords.
But a trip to Chelsea is about much more than fashion. On my first visit last year, I realised the show offers a chance to view cutting-edge garden design; to see some of the most beautiful plants and flowers in the world; to chat to gardening professionals and amateurs; and to join the 159,000 people who drink the 6,500 bottles of champagne and 18,000 glasses of Pimms. For dedicated followers of fashion, here's a tip: the trendy gardener's must-have for 2004 could well be "restios", a sculptural grass in shades of green and brown. And the outsider is: pink geraniums.
• The Chelsea Flower Show is open to non-RHS members on May 27th-28th. Tickets must be bought in advance. Website: www.rhs.org.uk/chelsea smarriott@irish-times.ie
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