It's gardening season, and garden centres everywhere are laying out their wares to attract unsuspecting novices, writes Jane Powers

It's Sunday afternoon, and Mr and Mrs Everyman load their two children into the back of the car and set off on the weekly jaunt. A visit to granny? A trip to the cinema? A walk in the country? Perhaps. But it's just as like-ly that they're off to the garden centre.

And once they've arrived, there's a strong possibility that one or all of them will completely lose the run of themselves. It takes an iron will to emerge unaffected from the garden centre of today, a place that has become a carefully-designed obstacle course of products pleading to be brought home - with many of those products having nothing to do with gardening.

On finishing the circuit, our now heavily-laden family may hardly recognise themselves as the same people who stepped lightly through the sliding doors some hours ago. In the intervening time previously unrecognised yearnings have surfaced, and have had to be satisfied: cravings for splashes of jolly pansies, scented candles, timber decking tiles, cast-concrete statuary, Louis XIV water features and nests of colourful pots manufactured in Vietnam.

The children, meanwhile, have had a stint in the playground, followed by a sustaining snack in the restaurant - both within the garden centre. Their patience has been rewarded by their parents, who have found cute canvas bags bearing the kiddies' names, cuddly toys, and a miniature set of gardening tools in eye-catching colours - although whether there will be any space to use them, in between the new decking, the splattering fountain and the feng shui lion effigies, is another matter.

The strange thing is that the interior of Mr and Mrs Everyman's house is a painstaking and co-ordinated picture of sophistication. It stands in stark contrast to the medley of styles that are fighting for the conquest of their garden. One reason for this anomaly, perhaps, is that they are among the 54 per cent of consumers who identify themselves as novice gardeners (according to an MRBI survey commissioned by An Bord Glas). As novices, they are - naturally - more open to impulse buys and the powers of suggestion than more discerning veterans of the soil. And successful garden centres, despite their association with the wholesome hobby of horticulture, are masterful selling machines.

As with supermarkets, customers are rolled in one end, and out the other - with the prime selling space covered over and sheltered from the elements, like a giant car port. Rachel Doyle, owner of the Arboretum Garden Centre in Leighlinbridge, Carlow, which won the Bord Glas National Garden Centre Quality Award 2003, confirms the importance of roofed-in space.

"A covered area is a must, it's where the impulse buying takes place. Most of our sales happen here." In many garden centres this is where the customers are exposed to handsome, in-season plants - which sell themselves by their flowers, berries or other timely charms. Wholesale nurseries send "looking good" lists to retailers to ensure that there is a year-round supply of tempting plants to seduce buyers. Observers of the "looking good" phenomenon can pinpoint exactly which months home-owners have visited garden centres - inevitably during the clement season - by the lack of winter and autumn colour in their gardens.

The customer is also exposed to the latest fashions in "garden design", generally as portrayed on prime-time gardening television.

Could it be that Charlie Dimmock of BBC's Ground Force, and the doyenne of ponds, fountains (and of the accompanying wet T-shirt), is responsible for the proliferation of water features in today's gardens? According to Rachel Doyle, "water features are big now", and she adds, "the power of the media cannot be underestimated."

The popularity of decking can also be attributed to Ground Force, as Alan Titchmarsh, erstwhile presenter told this writer over four years ago: "I get it in the neck now in Ground Force for using gravel, pebbles and decking, but it suddenly opens up the garden as an all-weather surface; a lawn isn't an all-weather surface". And sure enough, at the Arboretum Garden Centre, "younger people are not keen on lawns", says Doyle. "They want gravel, paving or decking." Money, of course, is more abundant now. "People come in, see something they want, and buy it." Such purchases may include mature plants, to feed the hunger for instant gardens: "€250 and €300 are commonplace for mature trees," claims Doyle, who also admits "the sky is the limit" - or rather, €1,000 for a 40-foot cedar of Lebanon.

With all this money floating around, sales in independent garden centres have risen by 55 per cent since 1999, to €137 million - which is not surprising, as major garden centres are now open seven days a week, all year. And in order to keep their staff on, many have diversified into selling everything for the "outdoor room". Besides plants, tools and landscaping materials, there are hot tubs, garden furniture and statuary, wind chimes, water features, patio heaters and barbecues.

For the house interior, there are potted plants, artificial flowers and "giftware": body-care products, novelty toys, household ornaments, jars of preserves. Restaurants, extensive car-parks and playgrounds are widespread, while the Arboretum Garden Centre even has a conference room and a bandstand. "You can come here and see someone playing a harp, and it's a real 'Wow!' for the customers," enthuses Doyle.

During the slack months of November and December, many garden centres metamorphose into Christmas shops, with container-loads of decorations and other seasonal fripperies. All of this, no doubt, is welcomed by consumers who expect all their leisure needs to be catered for in a one-stop shop. But it is a world away from the specialised nurseries of 25 years ago.

Then, many plants were grown from seed by gardeners, and shrubs were sold bare-rooted during the dormant season, having been carefully dug up and wrapped in burlap. Tim Wallis, of the National Garden Exhibition Centre in Kilquade, Co Wicklow, has been in the business for 30 years, and recalls, "People knew that the planting season was October to March. I remember noting in my diary that November was the busiest month of the year. And you might as well be closed for June." Now, he notes, sales starts in earnest with the May bank holiday.

The seed for this change was sown as far back as the 1950s, in the form of a simple plant pot. British nurserymen, on visiting the US, were intrigued to see "garden centres", selling ready-to-go, container-grown plants. By the 1960s, large nurseries in Britain were experimenting with polythene containers, and then, rigid plastic pots. Simply put, the availability of portable plants - whatever the season - has revolutionised the way we garden. "Today's garden centre presents it all on a plate," says Wallis. "People have more to spend, and they're more educated. They know what they want." But judging by the contents of some trollies, you'd have to wonder.