Gardeners’ World will be extended to hour-long episodes as part of a revamp under the producer responsible for the record-breaking last series of The Great British Bake Off.

The long-running BBC Two gardening programme – fronted by Monty Don – is back this week with a number of changes, after executive producer Paolo Proto was drafted in to oversee it.

Writing in a blog on the BBC website, Paolo said Gardeners’ World will move from a 30 to 60-minute format and a range of “new strands with some new faces” will be introduced.

“It’s an exciting time and one that offers a great opportunity to expand the breadth of gardening we cover,” he said.

Monty Don (Marsha Arnold/BBC)

New presenters will include “garden doctor” Nick Bailey, who will be solving people’s gardening issues, and Frances Tophill, who will meet people who “garden in extreme conditions”. Viewers will follow garden designer Adam Frost as he moves into a new house and sets about creating the garden.

Nick Macer will look at tropical plants and Florence Headlam will cover city gardens.

The main presenters – Monty, Joe Swift, Rachel de Thame and Carol Klein – will all return.

Rachel de Thame (Chris Ison/PA)

Gardeners’ World will celebrate its 50th anniversary next year and Paolo said plans are being made to ensure it is “an unforgettable year for gardeners and our legion of loyal viewers”.

Paolo was responsible for last year’s series of The Great British Bake Off, which drew audiences of up to 15 million and was the most-watched programme of 2015.

Gardeners’ World is on BBC Two on Friday.