A Green and Pleasant Land, By Ursula Buchan. Hutchinson, £20

Not everyone was "Digging for Victory" during the Second World War, particularly not my old headmaster's wife. Lady Trumpington, who last November starred in Have I Got News for You, hated being a Land Girl and escaped to join the Bletchley Park codebreakers, which was indoor work.

Still, someone had to get down to earth or Britain would have starved. Ursula Buchan has done a great deal of what can only be described as spadework to describe how gardening became a tool for the nation's wartime survival. For three consecutive years, no tomatoes were imported. Sometimes onions were so scarce that people gave each other one for their birthday.

Out went inedible, decorative plants. As the famous grower Harry Wheatcroft put it, "Pigs now wander about where our Polyantha roses bloomed." You were fined for growing strawberries instead of cabbages. In came vegetables and sensible fruit, shoehorned into country estates, parks and gardens. Alongside Dad's Army were Dad's allotments – 1,750,000 in 1943.

Dig for Victory provided "the most famous horticultural image of the war", a poster of a boot on a spade. The foot was that of a Stakhanovite allotment gardener – or maybe not. It was probably attached to the leg of an adman from an EC4 agency, snapped in a studio.

Whatever the truth, citizens were certainly exercising their green fingers. As its name suggests, the Bethnal Green Bombed Sites Producers' Association was one of many groups coaxing greenery out of ruins. Others found crops in the countryside. TV cook-in-waiting Fanny Craddock substituted bracken shoots for asparagus and served up hedgehogs and starlings.

Produced by a gardening columnist, this is a book in a lower key than classics such as Angus Calder's The People's War. But Buchan makes the powerful point that one of the conflict's great heroes was Lord Woolton, the Minister of Food: "No one starved." Even if they had to eat Woolton Pie, a turnip dish created by a Savoy chef. Lady Trumpington was, much later, to return to her roots: she became an agriculture minister.