The full Monty

"Not only did I suffer but since I started gardening again I'm actually having to slowly get back into it," he said.

"I lost the habit. It's like being a musician, you are rusty and you have to get acquainted again. We are going to have to get to know each other again - the garden and I."

Journeying across the globe for six months out of the last 18, examining people's lives via their gardens, led him to establish a very strict routine.

"When I was away the first thing I'd do every morning would be to get out my laptop and look through pictures of my own garden and go for a walk round it, via digital technology," he said.

"I never went anywhere in the world where I wanted to be more than I wanted to be at home."

doesn't have the travelling bug (despite four years on the Holiday programme), the new show did open his eyes to a world of gardens - and gardening - he didn't know before.

"There is a universal language of gardens," he said. "Even in the Amazon jungle with someone speaking to me in some very obscure dialect, you could see what they were doing and understand them. There was some level of communication.

"The two things that really come through is one, wherever I went in the world, all the most interesting gardens, without exception, were linked somehow to the place they were set in, by their plants, or their culture, or their religion," he continued.

"And the other thing is that most gardens can and should be an unembarrassed artistic expression. We should relish them as works of art. And I think they are - I think gardening is an art form and in this country we are rather obsessed with it as a science and as an aspect of horticulture.

"The obsession with gardening is certainly something that is completely unique to us," he said. "No other culture I came to found it necessary to put on the wellies and go out and get their hands dirty in the way that we do.

"We talk about a proper gardener' but I never came across that concept anywhere else in the world.

"Gardens are viewed for aesthetic pleasure or productivity, not for one's personal role in it. It is very rare for someone who could afford to pay someone else to do their garden to do it themselves."

So when Monty got stuck in among the locals in Mexico, Cuba and South Africa, they found it very strange.

"They tended to be slightly embarrassed," he laughed. "Who is this loony Englishman? Why is he wanting to dig and plant and weed?"

Still, getting involved was crucial to the host, who didn't want to be painted as some dilettante foreigner with a film crew.

The result is a reflective and beautiful travelogue, focusing on parts of countries we don't usually see.

However, he stressed: "It is not a top 80, it is not a list. The thing was to get under different culture's skins through their gardens. No-one has ever done that.

"Not only that," he added, "it was my choice and it was personal - not to say I didn't have very good researchers but it is my opinions. It was very much a personal trip."

Although he is glad to have done it, it is clear that Monty is relishing being home, with wife Sarah and the kids.

Mid-interview, his mobile rings - it is his son making sure that dad is coming to pick him up from school.

It is a tricky balance, juggling his work commitments to the BBC's Gardeners' World, which begins a new series at the end of February, and his journalism, with trying to rectify the damage done to his beloved garden while he was away.

"It did go into disrepair," he sighed, talking about it like a rebellious child. "It has never been so shaggy. But gardens have great powers of restoration, the are very robust."

Nonetheless, he won't be utilising any of the designs he witnessed on his trip in his own back yard.

"No, because you have got to be true to yourself," he said. "I make my garden because I like it. And if anything, I have got to have confidence to do my own thing, rather than try and pick this and that from all over the world."

Does he ever wish he was able to escape the mantle of being a celebrity gardening expert? Apparently not.

"I have always gardened," he said. "I was in my 30s before I even thought of earning money from gardening. I never dreamt of being on television. It came to me and it will leave me."

Which may be why he is translating the more basic essence of gardening into bigger issues. He recently tested his long-held theory that working the earth is therapeutic by taking a group of ex-drug addicts under his wing and getting them to help farm a six-acre plot of land with successful results.

Monty said: "I am also extremely interested in growing food. It's an extension of the landscape. I am extremely interested in the environment and that is directly connected to gardens.

"I am not suddenly going to get interested in politics. I do have other interests, but I'm not going to give up gardening, if that's what you mean!"