Candida Lycett-Green is best known for books that celebrate her love for the English countryside, including the best-selling The Garden at Highgrove, written with Prince Charles. In her latest book, The Dangerous Edge of Things, she uses real-life events, weaving the true story of the German nuclear spy Klaus Fuchs into her own memoirs of post-war childhood in village of Farnborough.

Meeting in her home in the nearby village of Uffington, at the foot of White Horse Hill, I asked her why she wrote the book.

"My last book, Over the Hills, was a complicated threading of a journey through cancer and a journey, on a horse, to Scotland, to celebrate being alive. I threaded various bits of my life through that book and I did a synopsis of my village life at Farnborough, the most idyllic bit of my life that anyone could ever imagine. I always thought I would like to write more about it.

"Then, I was reading a life of Klaus Fuchs, the spy, who was a Communist -- lots of people were communists in the forties, it was perfectly normal to be anti-fascist, after what we had all been through in the war. And I read that Klaus had always loved the Ridgeway and the Downs. This was common ground -- where we had played as children and where he walked. It was all going on at exactly the same time." The result is 98 per cent village memoir, with just the shadow of Fuchs and the spy scandal at nearby Harwell atomic research centre touching her life as the youngest child of the late John Betjeman, who was later Poet Laureate and remains one of England's best loved poets.

Like Fuchs, Betjeman is on the edge of village life, taking the train to London, or locked in his study, emerging now and then to attend some village event, like the arrival of electricity, or arguing with his neighbours over their politics or the demolition of a beautiful old barn.

"They didn't really figure in my life, my parents. I only remember meals -- apart from that I was out in the village or in our garden. We were out all the time."

She aware of Harwell as a child, but did not realise its significance until later. "It was a spooky place and there were all the rumours that people couldn't have babies if they worked there, that sort of thing -- the same sort of issues there are now about radiation. We knew there was this ground-breaking research that was going to get millions of people out of the mines."

The book paints an extraordinarily intricate picture of village life in the late 1940s. How did she piece the details together?

"It was absolute heaven to research the village life. None of the people live in Farnborough any more, it has become a posh village now. Ninety per cent of the cottages were tied to the farms, so when mechanisation came in the sixties and seventies, they were all made redundant because the farmers only needed two people instead of 20.

"There were 12 children in my school and I found eight of them. They were pretty far flung now, living in Swindon, Milton Keynes, Somerset, one still in Wantage, and I had incredibly long interviews with them. Two of the farmers were still alive, their sons still farm the same farms.

"Their recall was unbelievable, even what they had planted in which field; they have records of some of it. My hero, Terry Carter's mother, Dolly, had the best memory of all. She would say 'Oh yes, you came on a Tuesday, it was raining.' She was probably my main source. She remembered events and naughty things we did." The more people she spoke to, the more she remembered. "Really it is a collective village memoir. It is completely accurate. I even got the weather, how much money had been made at the whist drives, who had danced with who, from the Newbury Weekly News or the North Berks Herald." Add to this the music played on the radio, the films showing in Wantage, Newbury or even distant Oxford, and you have a complete picture of village life in 'the winter of 1947' and the glorious summer that followed.

"Farnborough was very late getting electricity because it was so remote. They had to get special posts to get the wires to Farnborough. We had the telephone. My Mum had a telephone and Mr Dowkes in the shop had a telephone. But when the electricity did come we couldn't afford to have it put up our drive. It was going to cost £100."

The lack of electricity and having to pump water at a handpump, coupled with her father's long (by 1940s' standards) drive to Didcot station every day, led the Betjeman family to leave Farnborough and move to Wantage. This was the sad end of a wonderful era, but Candida has recreated a loving portrait of a heavenly childhood high up on the Downs.

The Dangerous Edge of Things is published by Doubleday at £16.99.