Even Monet's famous paintings of his garden, considered the height of orderly beauty by today's middle class, were once considered an awful splodgy mess.

Those same conservatives probably think of the Chelsea Flower Show as the leading standard for their kind. A garden show might be considered challenging for horticulturalists . . . who can grow the best geranium or the cosiest privet hedge? . . . but it's not conducive to modern ideas of art. Well, it wasn't.

Until Diarmuid Gavin stuck his cheeky Irish mush into the fern plants and started messing around with concrete constructions and popular cultural references to Tellytubbies and alien pods. Now, it seems, to win a gold medal . . . and best in show, even . . .

you have to out-Diarmuid Diarmuid.

The Royal Horticultural Society this year gave its top accolade to Sarah Eberle's 'Life on Mars', a garden with more concrete than your average Readymix yard and fewer flowers than a suburban backyard after a windy day's spot-treating with Weedol.

But then Chelsea this year is all about art . . . or, in this case, theatre. Lisa Huntington, a garden designer and RHS judge, described the winning garden as "very brave and not to everybody's taste. . .

It's theatre and we need theatre."

The judges also felt we needed art . . . and high art at that. And so a gold medal also went to the winning garden in this year's newest category . . .

roof gardens, which, being a more modern idea in themselves, could be as eclectic and downright loopy as they liked.

'Patio Povera' is filled with discarded objects, including television aerials and tool boxes, and was the creation of 77-year-old Daniel Samuelson (with a little help from professional friend Daniel Lloyd Morgan).

I admit my first prole-like take on seeing the picture of this garden was that it looked like one of those awful unconsciously kitsch houses in middle America with the flag flying proudly next to plastic owls and dirty canary cages with dead canaries and feral cats in the house.

Though this garden also contains a bird cage, it encases a rather sexy-looking pair of red suede boots, the first hint that this is something cleverly thought out and designed rather than unconscionably allowed to happen.

Designed for his wife, the garden is based not so much on the plants as their containers which, according to Samuelson, are "objets trouvets" meaning 'found objects' . . . trust the French to come up with a charmingly sophisticated term for 'other people's rubbish'.

Gainsborough's 'Mr and Mrs Andrews' inspired the back centrepiece which consists of two lifesize window mannequins. The RHS website refrains from explaining what inspired the spider plantencrusted pair of naked legs and bottom, though we would like to conjecture that Samuelson is a very fit septuagenarian.

Further inspection reveals Mrs Andrews' hair as a plant called spotted deadnettle, the rubber chicken on her lap sporting, or I should say sprouting, common sage. All going to prove that art has always had a sense of humour and garden art is no exception.

Poor Diarmuid Gavin, who eschewed the follies of lollipops and spheres for a more traditional design this year . . . created, ironically, with an "art loving mature couple" in mind. He must be as bemused about this sudden conversion by the judges to the idea of gardening as conceptual art as the writer to the London Times.

"I have even less time for conceptual gardeners than I do for conceptual art, " wrote Kidd Garrett of Bristol, "unless it is me in a hammock, thinking about mowing the lawn."