How healthy are you?

I was a sickly child, and it wasn't until I was 19 that I realised I was quite a robust, vigorous person. Since then I've taken ill health to be an irritating interruption into what is a fairly reliable stream of good health.

Ever spent a night in hospital?

Yes, when I was a child I had bone-marrow cancer, and I also had my tonsils out. I spent a few nights in hospital last August with peritonitis. It was very serious, but once they had taken my appendix out and dealt with the infection I was packed off home after just four nights.

What exercise do you take?

From the ages of 18 to 50 I ran, rowed and lifted weights at my home gym. Now I keep my exercise focused on working outside. Gym culture veers too much towards appearance. I'm able to dig and chop wood, and I challenge anybody who goes to the gym to come and work with me outside.

Is sex important to you?

Yes it is. I've been married to Sarah for 25 years and sex has been a very key part of our relationship. I read something recently that said if sex is good it's 5 to 10 per cent of a good relationship; if sex is bad it's 95 per cent of a bad relationship.

Do you worry about your weight?

I would be a liar if I said I was totally undisturbed by it. I would like to be half a stone lighter, but I don't care that much.

How much sleep do you need?

I'm bad at sleeping. I get somewhere between three and six hours a night. I'll be in bed by 10.30pm and never have trouble going to sleep, but I usually sleep fitfully from about midnight until about 5am.

What's your attitude to smoking, alcohol and drugs?

I tried to smoke when I was younger, but I'm utterly unaddicted to nicotine. I use coffee and alcohol, though I haven't touched alcohol for two months. I think illegal drugs are unattractive and should only be used as a mild stimulant or relaxant, or as part of an enlightenment ritual. I've worked with addicts, setting up a smallholding to help them get clean, and I've found that drug use beyond a low level is fantastically unglamorous - it muddies everything. Having said that, I had morphine while I was in hospital with peritonitis, and it was blissful. Heroin is a painkiller, and you have to ask: where is that pain coming from?

Ever had therapy?

I had cognitive therapy for six months 15 years ago. It gave me ways of looking at things that I hadn't considered before.

Are you happy?

Happiness is a by-product rather than an end in itself. It pops into your life unbidden, and then tends to pop out again. I'm on record as being depressive. It is related to winter. I have used antidepressants in the past, but I gave them up 10 years ago when I started to use a lightbox on my desk. It's certainly helped. Since then I've battled through depressive interludes with the support of my family and by taking lots of exercise, cutting my workload, and by being outside. I'll say: 'I will get up' and 'I will shave' and 'I will muck out the chickens' - and that seems to work.

· Around the World in 80 Gardens by Monty Don is published by Orion, priced £20