Gardener Alan Titchmarsh's life was rocked this year by a sudden illness. He speaks about the drama and his life in gardening and TV

It was the moment Alan Titchmarsh - Britain's favourite gardener, best known for his calm and unflappable manner - admits he felt "very frightened".

"I hoped I wasn't going to die, and I was hanging on in there but the pain was so acute at one point I thought it might be a blessed relief," he says.

The TV presenter who's enjoyed enduring popularity over decades, appearing on shows from Gardeners' World and Ground Force to the Chelsea Flower Show, is talking frankly for the first time about the dramatic day in April when he had to be airlifted to hospital and underwent surgery.

With a family history of heart disease - his father died suddenly in 1986 from a heart attack at the age of 62 - there was obvious concern for the 67-year-old when he started suffering pains in his chest.

"The pain lasted and was absolute agony and every bit as agonising as a heart attack," he recalls. "At first I thought it was indigestion as I know that can give you chest pains - but it didn't wear off. I didn't know what was wrong and although I didn't think it was a heart attack, because the pain wasn't going down my arm (a common symptom), it was frightening.

"Actually I think it frightened my wife more, because of my family history, of course. The men in my family have a tendency to die from heart disease at a relatively young age."

After his wife, Alison, called the emergency services, Titchmarsh was taken to the nearest hospital to his Isle of Wight home, St Mary's and then airlifted to Portsmouth's Queen Alexandra Hospital, where he was diagnosed with gallstones and had surgery to remove his gall bladder.

Gallstones, one of the most common medical and surgical conditions, are believed to occur because of chemical imbalances in bile stored in the gallbladder. This can lead to tiny crystals developing, which can grow into gallstones, ranging in size from the equivalent of grains of sand, to the size of a pebble. The latter can cause extreme pain, often described as being worse than childbirth.

Although a diet high in saturated fat and pre-formed cholesterol increases the amount of the substance being pumped by the liver into bile, making gallstones more likely, Titchmarsh, who takes statins on the advice of his doctor to help lower cholesterol, says: "I watch my weight and am careful with my diet, and it was a rare treat that day to have home-made fish and chips followed by an Easter egg. It was just one of those things and quite unglamorous, but it pulled me up short I can tell you. Thankfully, after a straightforward operation, I haven't had any more trouble."

Yorkshire-born Titchmarsh, who this year appeared on ITV's Love Your Garden and hosted game show, Masterpiece, has clearly recovered his equilibrium and would rather focus on his latest novel, Mr Gandy's Grand Tour.

The book's hero isn't dissimilar to the author - a middle-aged man who enjoys painting, travelling and boats, and finds himself a magnet for attractive women.

Titchmarsh is modest about his own legion of female fans. "I never see myself as having some sort of attraction to the opposite sex. I don't really think about the secret of my appeal. At the end of the day, all you can do is be yourself and be genuine."

Inspiration for his plot, he says, came from a desire to explore the scenario of a man who'd remained in a long, unsatisfying marriage, but on becoming a widower, suddenly takes off on an adventure on his own.

"My wife always reads my books first and when she read this one she asked me, 'It's not about us, is it?' I said, 'No, of course not.' After all, P.D. James never murdered anyone, but she wrote brilliant crime mysteries. I just wanted to show men can be as sensitive as women and tell a good tale," he says with a smile.

"Alison and I have been married 41 years, she's my best friend, and family life - our two daughters, sons-in-law and four grandchildren - are at the heart of everything. I hope I'm romantic, but I think being considerate is just as important as gestures on occasions. Marriage is about thinking about the other person and enjoying one another's company."

Although he's been urged by his family to "take life easier," he confesses it's difficult because, "I don't want to retire as I think you need a sense of purpose and a reason to get up in the morning. So I'll always be a gardener, I couldn't do without that - it's part of me. I love the writing which is solitary and then I have a balance of the fun and socialising of the TV work. So far, it's a perfect mix."

There is one aspect of his fame he does find hard to handle - criticism. "I'm better than I was though and nowadays take it to heart for a shorter length of time. I'm sensitive by nature, which helps me as a writer, but you need a thicker skin in my other world of TV. I'm lucky I've found a group of folk who appreciate what I do but it still hurts if you do something and it's a disappointment," he says.

He undoubtedly enjoys Royal approval - recently the Queen gave him keys to the back garden at Buckingham Palace for a documentary, and he's toured Highgrove Royal Gardens with Prince Charles, who describes Titchmarsh as a "friend".

"It's very sweet of the Prince to say I'm a friend. We've known each other a long time now and I think he's the hardest working person I've ever met. He's totally committed to making the world a better place," he says.

"As for talking to the plants, for which he's been teased, I do the same. I threaten my plants if they're not doing well and say, 'You've got another week and then you're on the compost heap'."

While he acknowledges he still finds it "scary and rather shocking" that he's lived longer than his father ("You automatically assume your father will be senior to you forever") he's happy that he was able to witness his success.

"He loved seeing me get on and that's a big comfort. I'm very content and still happy to cope with the unpredictability of not knowing what's around the next corner. I still feel like someone in their mid-40s," he says.

"I'm often accused of being relentlessly cheerful, and in company, I am because why would you burden other folk with your problems? Anyway, I've got no reason to be grumpy, and if I occasionally am, I'll give myself a talking to. I've been incredibly lucky and never expected the life I have. Even now I expect someone to come up and say, 'Who are you and what the hell are you doing here?'. I think it's helped that I've always said 'yes' to opportunities, and I've never thought the world owed me a living. Gardening's opened so many doors for me and I think it can benefit everyone by keeping us grounded - no pun intended. When I'm at home, our garden's my special retreat.

"I look forward to my walk around it on Christmas Day. It's one of the most serene times of the year, when it's quiet all around us and I slip out. While most folk are sitting in front of the telly or tucking into another meal, I'll be out there taking stock and making plans."

:: Mr Gandy's Grand Tour by Alan Titchmarsh is published by Hodder & Stoughton, priced £18.99. Available now