Showtime!: Anna Pavord on pleasure and puzzlement at this year's Chelsea Flower Show

I backed the wrong horse. As everyone now knows, Andy Sturgeon won the award for the best show garden at the Chelsea Flower Show this year. I thought it would go – once again – to Tom Stuart-Smith, who created a scene so cool, so inviting (it was searingly hot at Chelsea), I just wanted to leap the boundary rope protecting the garden and lie spreadeagled among the cow parsley and iris. Actually, it wasn't cow parsley but something even better: Cenolophium denudatum. There's going to be a run on the stuff so get your order in quick. Crocus.co.uk can supply plants in two-litre pots at £6.99. If you have more patience, you can buy seed from Thompson & Morgan (£2.09 for 20 seeds).

What's good about it? For a start, it's got umbrella heads like fashionable ammi and orlaya, but unlike them, it's perennial. It has excellent foliage, dark green and deeply cut. And it is very generous with its wide, hazy heads of tiny white flowers – rather like our native cow parsley but better. Not quite so rangy in growth. Bigger, denser heads. Left to themselves, the plants would flower from July to September. Like so much stuff at Chelsea, these were hurried on a bit, so that the flower heads fluffed through the planting, at exactly the right stage, more green than white, full of promise.

This was the quietest, most restrained garden at Chelsea, but to me by far the most rewarding. Shifting patterns of shade came from four multi-stemmed river birch (Betula nigra) scattered through the long, narrow plot. It's a more subtle tree than the bright white B. jacquemontii. The river birch has reddish-brown bark that peels off in layers – a superb match for the extraordinary bronze pavilion at the back of the garden, designed by the architect Jamie Fobert. Fobert (he's currently working on Kettle's Yard in Cambridge and on the extension to Tate St Ives) designed the pavilion for a garden in Notting Hill, but the lucky owners allowed it to come to Chelsea first.

The underplanting of the garden was dominated by the cenolophium, with sheaves of papery white Astrantia major 'White Giant' carrying on the pale greenish-whitish tone of the planting. Mats of shiny-leaved Asarum europaeum reflected the sun, and that was important too, because both the astrantia and the Baltic parsley (cenolophium's common name) absorb light. The sharpest notes of colour came from the lime-green heads of two spurges (Euphorbia cornigera and E. wallichii), both rearing up a little higher than the umbellifers. Both hold their colour a long time, from late May right through to August.

Three different shades of blue were provided by clumps of Siberian iris – pale 'Perry's Blue', darker 'Tropic Night' and darkest of all 'Shirley Pope'. There was other stuff there too, fiddling around between the major players: white dicentra arching its elegant hearts over the greenery, pale lilac geranium 'Blauwvoet' humming a quiet lilac tune alongside aruncus and creamy white monkshood. Holding in the planting were drystone boundary walls anchored by differently sized balls of box, not formally spaced, but joined together like breadrolls that have been set too close together in the oven.

There were 15 show gardens this year and eight of them got gold medals (including Tom Stuart-Smith's). Though sponsorship remains a problem, the standard was exceptionally high. The number of show gardens provides another way of feeling Britain's financial pulse. Last year (the worst ever) there were just 13. But in 2007 and 2008 there were 20. The glory year was 2000 when there were 23 show gardens. Millennium money.

The show gardens always get the lion's share of the attention, but my heart remains in the great marquee, where the nurserymen, unsponsored by anyone, put up a more spectacular display of plants than you could see anywhere else in the world. Grower Johnny Walker had 76

different vases of daffodil on his stand, all brought from his Lincolnshire nursery. It was his biggest ever display and he had to start picking two weeks before the show opened, storing the flowers away from the heat in a giant fridge. He got a gold medal. So did Avon Bulbs who had worked all through the night to get their stand ready. The effort never shows and it was one of the most spectacularly beautiful stands they've ever done: searingly red gladiolus 'Mirelle' rearing up behind orange tulips ('Prinses Irene'); white Ornithogalum magnum mixed with the pale green bells of a fritillary called 'Ivory Bells'; magenta Gladiolus byzantinus teamed with orlaya. And a wonderful stand of the Dutch iris 'Apollo' which has been one of the great stars of our own garden during May.

I planted it on a steepish bit of bank where some of the iris had to push through the sprawling arms of a big rosemary. The lower petals (the falls) are soft yellow, the upper petals (the standards) are white, but as they age they drift towards a cool iceberg blue – a mesmerising performance.

Another way of measuring the country's financial state might lie along what's known as the Northern Road, the boundary with The Royal Hospital in whose grounds the Chelsea flower show is held. Traditionally, this is where the tractors and lawnmowers cluster together and four years ago 11 companies had stands there. This year there were just three: John Deere, Kubota and Bosch. A Chelsea without Atco? Is it possible? Evidently so.

There were other uncomfortable shifts, too. Stalls giving advice and information (surely something the Royal Horticultural Society should be encouraging) were down to 13, from 22 three years ago. Some bizarre new categories have appeared in the show catalogue's index: jewellery, spas, hot tubs, clothing and footwear of the non-gardening kind. In the "gift" category are 56 exhibitors, an increase of 25 on the 2007 figure. All of them can sell their goods. The nurserymen can't. There isn't enough room, say the organisers. So there are 10 stands where you can buy an apron, but not a single one where you can pick up a fern. The priorities need shifting.

Plants for both Andy Sturgeon's and Tom Stuart-Smith's gardens were supplied by the online nursery Crocus, who are having a rare open day at their nursery today (9.30am-4pm). Find them at Nursery Court, London Road, Windlesham, Surrey GU20 6LQ. For more information, check out the website at crocus.co.uk or call 0844 557 2233