There is not one real bloom or blade of grass. But in a clear sign that the Royal Horticultural Society is attempting to shrug off its stuffy image, judges awarded James May, the Top Gear presenter, a gold medal for his Plasticine garden at the RHS Chelsea Flower Show. The medal is also made from Plasticine.

The gesture was a clear rebuff to traditionalists who had accused the garden selection panel of dumbing down the show. Although May’s Paradise in Plasticine garden disobeyed the rules, the judges liked it — and even chose to ignore a gnome snoozing next to a pot of daisies in another flagrant breach of the rules.

In a letter to May they explained that he could not be judged under normal criteria because he had chosen to ignore the requirement to include real plants. However, in recognition of the appeal of his garden to children and the RHS’s drive this year to encourage a new and younger generation of gardeners, the judges wished to give him an accolade.

May was delighted with the tribute. He said: “Their letter to me was terribly polite but I clearly put them in a spot of difficulty because the rules said that real flowers must be in the plot. But we didn’t have any. But they seemed to quite like my garden.”

The display, made from 2.5 tonnes of Plasticine in 24 colours, attracted plenty of admirers on the first day at Chelsea open to RHS members.

There was much celebration among the Wessex and Jersey flower arrangers whose stunning display, Indoor Out, Outside In, won gold on behalf of the National Association of Flower Arrangement Societies.

The display is sponsored by the Army Air Corps, which had given the women the loan of a hangar to create their display. At Christmas their work was disrupted when they were forced to move to a new site so that the hangar could be used to store a helicopter used by Prince Harry on his training programme.

The Queen paid particular attention to the displays of pinks, lilac, roses and hydrangeas and chrysanthemums planted in glass baubles and pots.

Ulf Nordfjell, the Swedish designer, won gold for his creation, which was judged Best Show Garden.

Times recommends

• Second homes: credit crunch casualty or money-spinner?
• How I built my own sliding house
• Top 10 incentives for house buyers