Diarmuid Gavin is to become the Willy Wonka of the gardening world.

TV gardener Diarmuid Gavin

The Irish design maverick plans to build a giant ‘magical’ garden themed around chocolate at the RHS Hampton Court Palace Flower Show on 9 to 14 July.

It will be the biggest garden ever at Hampton Court. The only snag is that Diarmuid is yet to secure sponsorship, and needs to raise a six-figure sum.

“The garden is themed around and inspired by a magical chocolate world, with cola plants and chocolate smells,” said RHS head of shows development Bob Sweet.

“It will be bigger than anything seen at Hampton Court before.”

Diarmuid’s garden will feature cypress trees, topiary balls and under planting. Steps will lead up into glass-fronted shipping containers, while visitors will be able to walk through the garden.

Diarmuid will not be at the RHS Chelsea Flower Show this year, after applying without a sponsor in place.

He said: “I’m thrilled not to be there [at Chelsea]. Let’s just say we were made an offer we couldn’t refuse.”

His Hampton Court chocolate garden is likely to take centre stage at the event – a space once occupied by the Daily Mail’s ‘dream cottage’ pavilion.