Where do you go if you want to buy wholefood or stroke a pot-bellied pig? To a new-style garden centre, of course. Helen Chappell reports
On a hot Sunday afternoon the sounds of the fairground fill the air. Monkeys squawk at the rattle of wire shopping trolleys over gravel, children shriek with laughter and the whistle of the miniature railway train calls everyone to take a ride. It might be an amusement park or holiday camp anywhere in Britain, but it's not. This is a garden centre. Not your common or garden garden centre, however. The Van Hage Garden Company in Amwell, near Ware, Hertfordshire, is in the vanguard of a retail revolution - a new generation of all-singing, all-dancing centres that aspire to be the leisure palaces of the 1990s .

In the "Van Hage Experience" there is certainly no shortage of plants: bedding plants, house plants, dried and polyester plants and a floristry studio. But plants are no longer enough. You are also offered a fun day out for all the family in the home decor and gifts departments, wholefood store, book store, Frog Club children's shop, kiddie zoo and miniature railway ride. This bewildering array of diversions is being tasted by a motley crew of punters today. White-haired matrons in acrylic cardigans are fingering trays of hybrid begonias while chic thirtysomethings muse over terracotta urns and wrought iron candelabra for the conservatory. Young couples struggle to control toddlers who have just spotted a concrete puppy or (real life) Vietnamese pot-bellied pig. They are watched by a giggling band of teenagers lighting up illicit fags on benches in the low-maintenance display garden.

"Van Hage's sort of garden centre is definitely the way of the future," says Ken Allen, chairman of the Garden Centres Association. In his view, it won't be long before a similar emporium opens up at a drive-in site near you and your Sundays and bank holidays will no longer be your own. There are vast profits to be made. Thirty million people already visit garden centres every year. Eighty-five per cent of British adults have access to their own garden. The keenest gardeners are between 35 and 64, but even among the garden-hating under 25s, 70 per cent own their own plot. The trick is to get them excited enough about it to loosen their grip on their credit cards. The more new attractions a centre can offer, the more cash goes into the till.

"It all started when garden centres got into Christmas," reports Ken Allen. "This was such a mega success that we've now got the Santa's grotto and Christmas decor market sewn up. Soon we started looking for other ways to overcome our traditional enemy - the weather - and make our customers come to us all through the year." Instead of laying off staff during wet spells and winter, garden centres such as the UK top four (Wyevale, Nottcutts, Country Gardens and Hilliers) are branching out into under-cover lines such as conservatory and patio planting, floristry and even home decoration. "Although plants are still our big seller," says Ken Allen "some of us are starting to wonder if we are losing our roots. But when it is bucketing down with rain in February, our staff have still got to pay their mortgages, haven't they?"

It's a trend clearly welcomed by today's fun-loving gardeners at Van Hage. Louise and Neil Olley from Bishop's Stortford and their sons James, aged three, and Thomas, aged two, are sauntering past a psychedelic display of lupins toward the sound of the miniature railway. "It's the second time we've come," enthuses Louise as James clasps her thigh, "because it's a cheap day out with lots for the kids to see and do." Thomas clings to his father's shoulders and inserts a finger in his left nostril. "As long as you don't buy anything, that is," says food technologist Neil. "It is a bit expensive, though it's well geared to the family. You don't have to keep the kids quiet, they can run around in the fresh air."

Inside the patio department, Hertford couple Alan and Marian Greening are peering at the plumbago and passion flowers. These customers look a touch bohemian; Alan with his greying hair in a pony tail and Marian with her ankle-length skirt and Peruvian knitwear. What do they think of the total garden centre experience? Marian, an antiques dealer, twirls a potted clivia and narrows her eyes shrewdly. "They know how to arrange and sell things," she says. "They realise how obsessed we British are with our gardens and have found ways to give us everything we want under one roof."

If this is true then the statisticians at Mintel will be pink with pleasure. All their recent findings on the gardening industry are apparently being acted upon. It has taken a decade or so for the snobby world of British gardening to decide to run away and join this retail circus. But then, as the latest Mintel report makes clear, gardening is a funny old market. On the one hand, it has been surprisingly recession-proof. On the other hand, the stagnation in the housing market has meant that fewer young couples are now able to buy a home with a garden, replacing the high-spending middle-aged and elderly gardeners as they die. In fact, Mintel reckons a saturation point in garden ownership has been reached. So garden centres now have to appeal to all ages, sexes and pockets. Hence the something-for-everyone ploys of the new generation centres.

Marin Hoyles, a senior lecturer in Community Studies at the University of East London and author of The Story of Gardening (Pluto Press), believes there is also a deeper reason for the new age of garden centre worship. "More and more people are working long hours in boring, high-tech jobs," he points out, "and losing touch with the natural world. Garden centres provide a vision of an earthly Utopia where there is honest toil that uses mind and body and isn't dominated by the clock." He also notes a growing trend toward an open-air festival culture, replacing the traditional damp British fete. Even young people are feeling the urge to get out in the open and close to the soil. He finds no difficulty attracting students to his new course on gardening and contemporary culture.

All of which may not be of burning concern to the gaggle of twentysomethings clustered around Van Hage's garden ornament display (naked nymphs at pounds 760, playful hippos for pounds 39.95). "We're here to get some ideas," says Wayne Martin, a graphic designer. "We want to landscape our garden a bit and put in a barbecue.'' Shouldn't people their age be clubbing and pubbing rather than pottering about in the garden? His wife Julie shakes her head vigorously. "If you're proud of your home you want your garden to be nice, too. We're going to sort out the garden now and then we can use it for parties."

Mintel would be proud of them. They would also be thrilled to see the white-haired couple stopping to let their grandchildren play with the concrete crocodiles and gnomes. "Can we go and see the Wendy houses now, grandad?" chorus the tots as a procession of pushchairs, Zimmer frames and wheelchairs trundles past them. Worried about the future? Want to know where the British are going as a nation? Come into your local garden centre, Maud. Rain or shine, most of us will be down there already.