Chelsea's not just about flowers. It's about gardening with balls. Apparently

Rising high above the garden on metal spikes is a row of multi-coloured spheres. Hidden at one end is a curving playhouse, covered with smaller balls and containing a retro-chic bubble chair, possibly last seen in a 1970s sci-fi movie.

Rising high above the garden on metal spikes is a row of multi-coloured spheres. Hidden at one end is a curving playhouse, covered with smaller balls and containing a retro-chic bubble chair, possibly last seen in a 1970s sci-fi movie.

Its designer, Diarmuid Gavin, the hot young garden creator of the moment, says the influences at work in his National Lottery-sponsored garden, entitled "A colourful suburban Eden", are the Festival of Britain, Damien Hirst's spot paintings and the Teletubbies.

"I think it's complete crap and a total waste of lottery money," said one passer-by, who declined to be named. Welcome to press day at the Chelsea Flower Show, which this year has decreed officially what visitors have come to realise over the years, that it's not just about flowers. It is, apparently, about foliage.

There certainly were not many flowers in evidence at Gavin's garden, which was attracting plenty of attention, including complaints. "I can't believe how awful it is," was one of the more printable comments of Jane Priory, from Hampshire, who was visiting a friend's stand. "I just don't think the planting works at all, there's nothing to gain inspiration from for the average gardener. I mean, who's going to put all these coloured balls among their roses?" Her companion, Anne Wright, chipped in: "And if it wasn't for the balls, no one would be looking at it, would they?"

Gavin, with his untucked shirt, fashionable jeans and winning personality, is the latest representative of the television-fuelled "garden-designer- as-auteur" phenomenon, a class to which the similarly tousled-haired Dan Pearson belongs but Alan Titchmarsh, Monty Don and Charlie Dimmock, all present and correct yesterday, probably do not.

But all are members of a new generation of garden enthusiasts for whom gardens have become outdoor rooms and lifestyle extensions, complete with water features and spiky grasses. The older brigade are represented by people such as Julian Dowle, who has been designing award-winning gardens at Chelsea for more than 20 years. This year's garden, which may be his last before retirement, is a display representing "from darkness into light" for the Salvation Army and builders' merchants Buildbase. It uses the colours of plants and flowers to illustrate the transition, beginning with black grasses and ending with white roses. "It's a bit of theatre, isn't it?" he said, nodding in the direction of Tellytubby land. "I hope my gardens contain things like colour schemes and planting ideas that people can look at and say: 'Well, I can do a bit of that at home.'"

He accepts that Chelsea is not the same place as it was when he designed his first garden in the 1970s for £2,000. "Then you were lucky if you got a corner of your garden in shot when the Queen walked by. Now the expectations of sponsors are unbelievable and it is becoming more extravagant every year."

He added: "I hope it does not become too remote from the average gardener and I think it is very good that there is still an emphasis on small gardens."

Certainly Chelsea is about more than flowers. It's all about showbiz, corporate sponsorship and celebrity endorsements. But there is a more serious side this year, with the show's creator, the Royal Horticultural Society, which is celebrating its 200th anniversary, stressing the importance of gardening and the environment. It is insisting that all wooden products come from sustainable sources, while many of the show gardens are based on themes such as biodiversity and recycling.

The National Trust and the Henry Doubleday Research Association, Britain's main centre for organic gardening, have also launched a project to identify organic methods of growing roses - the country's favourite plant is notoriously susceptible to bugs and pests normally treated with pesticides. There is also an allergy-free garden.

Although large quantities of Pimms and champagne will be consumed by the linen-suit brigade this week as they admire the endless floral arrangements from the shires, Chelsea is also no longer simply part of London's "season" alongside Ascot and Wimbledon. Thanks to television programmes featuring Gavin, Dimmock et al, it's about the enduring appeal of gardening to just about everybody. Where else would you find a photographer for The Sun snapping a pouting young girl in a bikini top just across the aisle from a soprano in a bright red evening gown attempting to sing the virtues of her sponsor? The soprano gave up.