William Wallace: Dig for victory in the allotment revolution

BRITAIN imports half of the food its people consume. The shift to supermarkets, buying in bulk from overseas suppliers and shipping pre-packed produce around the country from central warehouses has sharpened the trend away from local production.

You can find beans from Malawi on supermarket shelves more easily than those from Monmouthshire and apples from Spain more easily than from Suffolk.

Worse, bulk supplies with "best by" dates lead to huge amounts of waste, with a significant amount of supermarket food ending up as landfill. With world food prices rising, the Government has just sounded the alarm. Hilary Benn, the Environment Secretary, has called for a strategy for national food security.

Happily, there is a counter-development under way. More and more people in Britain are growing some of their own food, after a long period of decline. Sales of vegetable seeds have been increasing for several years. Allotment sites that had vacant plots five to 10 years ago are now fully-worked, with long waiting lists. Young families are taking on plots, alongside the older generation who had held on through the years when affluence had left many plots empty. In the same way that real ale enthusiasts revolted against homogenised beer, promoted by multi-national companies, so fruit and vegetable gardeners have revolted against standardised food.

Home production, in gardens and allotments, will not of course close very much of the gap. A major shift away from over-dependence on imported food will require not only greater support for farmers' markets and local food shops, but also active co-operation from the supermarket chains themselves, and a transformation of their relationship with British farmers.

The recent shift in supermarket purchasing towards imported milk and milk products, as international prices have dipped, has shown that Britain's major food marketers do not regard their domestic suppliers as long-term partners and stakeholders. It will require a sustained campaign from consumers and politicians to persuade the dominant chains that support for British farming should be part of their business model.

Nevertheless, the revival of food production in gardens and allotments has an important role to play – as well as other, wider, benefits. My wife and I, now in our second season sharing a plot in Saltaire's Canalside Allotments, have experienced them at first hand. We're eating food within hours of picking it. We're growing and eating vegetables that it's hard to find in the shops: unusual varieties of squash and potatoes, Swiss chard, cavallo nero, Jerusalem artichokes.

Our tomatoes taste far better than the hydroponically-grown ones in the supermarkets; our carrots are delightfully sweet. We collect whatever mix of salad leaves we want through the summer. We're eating seasonal vegetables through the year, learning how to store onions and garlic, and buying much less from shops.

Britain imports half of its vegetables, but 90 per cent of its fruit. English apple, pear and plum orchards that used to supply our needs have been grubbed up; it can cost more to pay people to pick English currants and strawberries than to fly in supplies from abroad. Here again, gardens and allotments can fill some of the gap.

Varieties of apples, pears, plums and gages that have disappeared from commercial sale are being ordered in growing numbers from specialist nurseries. Some allotment sites are now planting communal orchards. We ate the last of our 2008 apple crop, stored in our cellar, this February. Our freezer is full with this year's soft fruit surplus, as well as summer puddings for later use and home-made strawberry ice cream.

Communal gardening has other advantages. Children learn about how food is grown, and learn to appreciate and value fresh food – instead of getting fat on fast food. Neighbours get to know each other, sharing advice, spare seedlings and surplus produce. Fresh air and exercise benefits people of all ages.

For those laid off from work in the recession, gardening both saves money and provides occupation. Those whose parents came from the Caribbean or South Asia can (and do) grow exotic crops that suit their taste.

Beyond these informal benefits, gardening projects have demonstrated benefits for young offenders, disabled and partially sighted people, and asylum-seekers not allowed to undertake paid work. Gardening also promotes recycling; allotment-holders compete for the size and quality of their compost heaps, and the imaginative use of rescued planks and plastic containers.

The greatest obstacle at present is the shortage of available land. Many councils developed underused allotment sites 10 to 20 years ago,

and are reluctant to invest in extra sites until they are certain that the surge in demand is more than a passing fashion.

There are estimated to be 100,000 would-be allotment-holders across England: enough to make a useful dent in food imports. Developers in Leeds have eased the pressures by providing land for temporary allotments in the city centre. Some groups have banded together to work underused gardens; the vicar of Rawdon, near Leeds, has invited people on the allotments waiting list to share her large garden plot.

This part of a national food strategy should best be left to local action. The Allotments Regeneration Initiative, funded by a private foundation, has provided regional mentors for local efforts. Parish councils, where they exist, have powers to control and expand allotments.

We shouldn't be waiting for the Government in London to tell us what to do. Get out there and dig!

Lord Wallace of Saltaire is Lib Dem spokesman in the Lords on foreign affairs and defence.