Do you still enjoy your garden?
Oh good Lord, yes. I've been gardening for a living for 51 years [he's 66] and I did it for quite a few years before then. It's just what I do; who I am.

You revealed that your new Isle of Wight home came with a hot tub. Have you kept it?
I don’t know anybody who’s got in one who hasn’t decided they’re the best thing since sliced bread! It came with the house and we thought we’d get rid of it. But it was working so we thought we’d give it a go. Oh my goodness! The worries of the day melted away and I’m sorry, but I’m now a fan. I’m totally addicted.

Does it interfere with your gardening?
The key is, you have to plant around it really well so it blends in, because they’re not pretty to look at. You sit in the thing, looking out at pretty things. It soothes the aches and pains, I tell you. My wife Alison [above right] has a dodgy back and it helps her, so it’s fantastic.

Why does a garden make such a big difference to your quality of life?
Because it’s your solace. An Englishman’s home is his castle, but his garden is his way of keeping in touch with reality, and nature. It has its frustrations, but don’t be too ambitious, just make it a sanctuary that suits you. And slow down, watch it, and get the pace of life sorted.

What advice do you have for people who feel daunted by gardening?
Just take a corner. Garden little and often, because then you enjoy it and it’s not a huge, laborious chore. People dig an enormous vegetable patch and after two months think, “I can’t do this any more.” You need to potter.

You’re back this week with a new series of ITV’s Love Your Garden. Whose gardens are you overhauling in this series?
It’s about creating gardens for people who really deserve it and whose lives will be changed considerably by having them. So we have a retired couple who were flooded out in Somerset, the youngest-ever recipient of the George Cross and, this week, a young woman, Nina, whose husband died of cancer and left her with three small children.

Do you get emotional when filming?
Every time! I find it very difficult to do the voiceover. I often have to stop at the end and do it again because it’s so moving. When lovely things happen, when somebody does something unexpectedly kind, that always moves me to tears. We beat ourselves up in this country about our attitudes, but I think we’re a kindly bunch. We don’t like to see people suffer.

Why did you decide not to bring back your ITV chat show?
I loved it, but I did hundreds of programmes over eight years: two per day, for two months. It’s a pretty tall order to research ten guests or more per day. It gets very tiring. Graham Norton, bless him, is doing one show a week. Also, I’d interviewed pretty much everyone I wanted to. I wanted to go before people said, “Oh him again, hasn’t he had enough?”

If you were offered a weekly chat show like Graham’s, would you take it?
Oh, I’d leap at it, yes. That’s quite different. I’m not whingeing. I was extremely well recompensed for it. But it takes a hell of a lot of energy.

Who was your trickiest ever interview?
Bette Davis walked out on me on Radio 2. That’s the one I’ll never forget. I was trying to be a bit sparky, but she confiscated the tape and wouldn’t let us run it. Since then, I’ve done one or two interviews with actresses who really don’t want to be there. And I think, “I’m only here to show you off, not to catch you out.”

Care to name any...?
Certainly not! There’s one on my mind at the moment, though, who I’d done twice and was hard work. She was inadvertently booked again and I said, “No, she’s hopeless, I’m not doing it”, but they said they couldn’t go back on their word. So she came on a third time and – yep, just as bad as the other times.

Who would you love to interview?
Maggie Smith, but she doesn’t do interviews. There’s probably a reason for that, she may turn out to be like my actress friend... I only want to interview people who want to be interviewed by me. It’s safer that way.

What’s your favourite TV viewing?
Watching CBeebies with my grandchildren (two boys and a girl). We’ve worked our way through In the Night Garden, and now we’re watching Meet the Pups. There’s nothing nicer than having a small child under each arm, sitting quietly. They’re allowed a bit of TV at the end of the day to calm them down. It’s lovely.

And what can’t you stand?
Rolling news. I like my six o’clock news or my ten o’clock news, but nobody needs news around the clock. I find it very self-serving: the only people who need rolling news are newscasters. And most of the time, all they’re saying is: “We don’t actually know what’s happening yet, but we’re trying to find out.” What’s the point of that? I will wait until they’re ready to actually tell me something concrete.

You’ve done pretty much everything. What about a reality show?
Oh, no. I can’t stand the Big Brothers of this world. People being horrible to each other makes me so uncomfortable. I’ve been asked to do I’m a Celebrity... Get Me Out of Here! but I wouldn’t inflict myself on the public. Whingeing is something I ought to do quietly on my own, not in front of an audience.

The only one I’d consider is Strictly because it’s learning a skill. I’ve been asked to do it several times, but my schedule wouldn’t allow me. To do it well, you really have to clear a good three months. Maybe next year – but then, of course, the body will have gone... And also, I know they’d make me the silly one with the bow tie, not the one with the shirt undone to the navel. And that’s sad, really. My days of having the shirt undone to the navel are long gone, I fear.

Love Your Garden is on Tuesdays at 8.00pm on ITV