Whole Foods? Don’t talk to me about Whole Foods,” fumes Guy Watson. “They’re a bloody disgrace. I think that the prices are ridiculous.”

Ever since Watson’s Damascene conversion in the mid-1980s, when he chucked the keys to his swanky management consultancy off the New York docks and returned home to Devon, he has been an outspoken champion of organic farming — and an equally outspoken critic of the “greenwash” that so often comes with it.

As the man behind Riverford Organic Vegetables, he has made £40m from supplying 45,000 customers with a weekly organic vegetable box. So great is the demand he’s had to set up a co-operative of several farms just to keep up supply. Now, along with Jane Baxter, head chef at Riverford’s farm restaurant, he’s written the Riverford Farm Cook Book, full of scrumptious recipes that make the most of his produce. But Watson has a combative personality: indeed, at times his book seems closer to a declaration of war on our wasteful and hypocritical society.

He has trenchant views on everything from TV chefs and anti-organic scientists to biofuels. And he believes that high-end organic brands such as Daylesford and Whole Foods make people think buying organic is a privilege of the rich. “Organic food should be accessible to everyone,” he says crossly. “People who use an ‘exclusive’ tag to build a brand make me angry. That’s not what it’s about. We try to keep our veg affordable to anyone.”

And he starts to foam at the mouth on the subject of supermarkets (honourably excepting Waitrose): “dehumanising” and “unspeakably unpleasant” are just two of the epithets he attaches to them; their buyers “make second-hand car salesmen seem like priests”. When he first rang Safeway to offer them his veg, the buyer asked him to come in on a Thursday. When he said Friday would be more convenient, the phone went dead. Watson rang back. “I think we got cut off,” he apologised. “No, sonny,” said the buyer. “When we whistle, you jump.”

But he reserves particular loathing for Sainsbury’s, whose gentlemanly facade, he says, hides a culture of sharp practice. “The final year we dealt with them, we agreed a price through our packer for our lettuces. A month in, they announced a six-week promotion on lettuce and wanted us to sell them at 9p each, having agreed a 14p minimum to cover the costs of production. We were regularly being featured in the Sainsbury’s magazine, and having executives come down to fawn over us, then the buyers would pull stunts like that.” Of the big four, it is only Tesco for which he appears to have a grudging respect. “They are what they are. You know you’re dealing with out-and-out barrow boys,” he says.

He has no time whatsoever for any newly discovered green credentials, either. “For example, M&S gives next to no information on how its excessive packaging impacts on its Plan A. They’ve had a huge amount of public support, but cynically avoided addressing this key area. They’re all making noises about wanting local produce and looking after their suppliers. I don’t believe a word of it.”

These days, Riverford is big enough to do without the supermarkets — a state of affairs that Watson, 48, admits he could never have envisaged when he first had the idea in 1986.

Ironically, he was brought up on a demo farm for ICI, his father being a progressive farmer keen to try out new ideas and chemicals. At eight, Guy was given a pig to raise; by 11, he was selling manure. He studied at Oxford University, then spent two years as a management consultant — “stimulating but morally bankrupt” — before returning home. “I had the idea to go organic when I was ploughing a field,” he says. “I’d spent time looking for emerging markets, and didn’t like pesticides: I’d made myself sick spraying corn, and my brother had been in hospital with Paraquat poisoning. The philosophical side came later.”

Now a fully fledged believer, he says organic farming “makes you a better person”: “Fighting against nature is an incredibly arrogant and misguided approach to living on this planet. You have to work with nature, and you can only do that if you understand it. You have to be more humble and sensitive.”

Another report hit the headlines recently, dismissing organic food as a “lifestyle choice” that will be choked off by the credit crunch. Watson, whose business is still growing by 10% a year, is having none of it. “Everyone accepts that organic food is higher in nutrients, but our scientific community has got it in for organic farming because we took a strong stance against GM crops,” he says. “Anyway, you’ll get more pleasure, confidence and excitement cooking with organic vegetables. That’s got to be better for you, hasn’t it?”

Riverford Farm Cook Book is published by Fourth Estate at £16.99. To order it for £15.29 (inc p&p), call The Sunday Times BooksFirst on 0870 165 8585 or visit timesonline.co.uk/booksfirst

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