Gardening routinely ranks high in the list of great British relaxations. But not quite so highly as the No 1 national hobby, which is complaining. How wonderful for the nation's green-fingered grumblers, then, to be able to indulge both their favoured pastimes simultaneously in the run-up to our greatest annual celebration of the floricultural art, the Chelsea Flower show.

Exhibitors there have been enjoying a good old moan about the huge variety of barriers to success this year. First there was the long winter, the coldest for three decades. Poor temperatures and low levels of light mean that the plant world is three weeks behind schedule. Then there have been several recent nights of minus 3C frost, the volcanic ash, the recession, the Australian bush fires – don't ask, or they'll tell you, and at length.

But the final straw is that the weather is now too darned hot. London has been sweltering in the mid-20s and is forecast to get even warmer by Tuesday when the show opens. Will everything flop in the muggy warmth? Good job gardeners are eternal optimists.