He's the nation's favourite gardener, a TV interviewer, an author of countless gardening books and novels. If that wasn't enough he is now gracing our screens as the historian of the evolution of the British Isles. Prime Time's David Barnett meets the new all-action Alan Titchmarsh

I'M not quite sure how we got on to the subject of windfarms, but we did.

He's talking about sacrificing the countryside "on the altar of economy" and saying: "I'm very ecologically minded, obviously, but I'm just not for windfarms. I'm worried about what they do to our landscape."

I guide him gently back towards the matter at hand; discussion of his new TV role.

Immediately, his outlook brightens. "It's absolutely brilliant," he says. "I've seen so much of Britain. It really is a wonderful, wonderful place, you know."

British Isles: A Natural History is now mid way through its eight-week run of hour-long programmes of epic breadth and stature.

The series has already seen this gentle gardener travelling from one end of the country to the other at dizzying speed in a jet fighter plane.

He has broadcast from the giddy heights of Ben Nevis and has been deep underground at Gaping Ghyll in North Yorkshire, which contains a waterfall twice the height of Niagara Falls.

This gardener who has over the years encouraged thousands of us to get our hands dirty is now very much an action man.

But according to the 55-year-old he is merely going back to his roots.

It was as a youngster that he joined the Wharfedale Naturalists Society in his native Yorkshire from where he first gained a loved of plants.

This led to him leaving school at the age of 15 for a job with Ilkley Parks Department and in turn an apprenticeship at Kew Gardens.

His work as a horticultural journalist, firstly on books then as deputy editor of Amateur Gardening magazine, broadened his knowledge of the subject which has made him a household name.

For six years he presented Gardeners World from his own two acre garden at Barleywood, Hampshire, showing us all how it should be done.

Groundforce brought gardening into the mainstream and it seemed that he could now rest on his laurels after the success of his TV career, his 40 gardening books and string of novels.

But offered the chance to take on a role which would involve 18 months of filming in the farthest-flung corners of the country and the need to climb the highest peaks and travel at 600mph to get a bird's eye view of the coastline, he could just not turn it down.

"I've always loved challenges and stimulation," he said.

"I'm not really looking for the easy life."

And he said filming for the series had filled him with wonder.

"You realise that the country is full of a lot more than you knew. People are very quick to travel all over the globe because they don't like the weather here, but we've got the most wonderful country right here and it's been shaped by that very weather. Britain is absolutely full of hidden treasures."

When he's not filming or gardening back at the home he shares with his wife Alison, Alan's doing his other main job - writing.

His latest novel, Rosie, published by Simon and Schuster recently, is selling well.

Now with two new gardening TV shows lined up as well as a top secret project which will see him branching out into yet another new area there really seems no end to this man's talents...or energy.