Urban gardener, Cleve West: Future farming

It was encouraging to hear at our allotment open day recently how more and more plot holders are growing their food organically. Organic gardening has come a long way. Once ridiculed, it's now widely accepted, and enough time has passed for those who have been lifelong practitioners to see exactly what the effects have been and where it might lead. One such pioneer is Iain Tolhurst, a stock-free organic farmer who sells 400 boxes a week from a two-acre walled garden and a further 16 acres of open fields on the Hardwick Estate in Oxfordshire. Known locally as 'Tolly', he has become one of the most inspirational experts on stock-free organic farming and advises regularly on his techniques both at home and abroad.

The Stock-free Organic Standards outlines a method of farming that doesn't rely on animal manures or by-products to fertilise the soil. It also restricts the use of 'natural' pesticides that are still unable to discriminate between 'pests' and beneficial insects. Instead, it uses a combination of green manure (sown as a ley, or grassland crop where there is space and as a companion crop between vegetables) and long crop rotations to optimise fertility and reduce the damage caused by pests and disease to a manageable level. What Tolly has done is to remove conjecture from the equation. Over the past 20 years his methods have been tried, tested and honed to dispel the myth that animal manures are essential to maintain soil fertility. This closed-system - which includes buying and selling locally to reduce environmental impact - is fast becoming a benchmark for organic farms across the country and around the world.

Tolly's decision to explore the stock-free method wasn't so much borne out of compassionate grounds but from the difficulty some organic farmers have in sourcing enough organic manure to fertilise the land.

The stock-free approach means that farms can become almost completely self-sufficient in terms of fertiliser. By adding 'beetle-belts' - overgrown strips of land between crops to provide food and habitat for insects - a natural balance evolves where predatory insects feed on slugs, aphids and other 'pests'. There are, of course, huge differences in terms of scale when comparing a farm to an allotment or garden, where damage caused by pests or disease is felt more acutely. But Tolly's methods are proof that by working with nature, not against it, sustainable farming can leave both us and the environment in a win-win situation. In larger gardens and allotments, green manures can be used successfully; in small gardens, kitchen-waste and home-made compost.

The difficulty lies in relying on neighbouring gardens to avoid using pesticides. And Tolly reckons on seven years of organic gardening to achieve a decent balance. It's probably safe to assume, therefore, that it might well take much longer in an urban environment. A sobering thought perhaps, but with a noticeable reduction in the amount of insects in gardens these days, there has to be a start. For example, encouraging architects to design green roofs for new developments to offset the amount of green space lost to concrete and Tarmac. Government grants for homeowners would also make a difference. Those with larger urban gardens that back on to other gardens or green spaces should be encouraged to let the far end of their gardens go wild in order to form thickets of undisturbed vegetation. This would provide cities with more trees to help offset carbon emissions - and green corridors or urban arteries to provide relatively safe havens and thoroughfares for wildlife. This, in turn, would help to breathe new life into our threatened biodiversity.

It might shock those whose notion of a good garden is mown lawns and tidy borders, but gardeners are uniquely placed to actually do something about our immediate surroundings; we need to make it clear to the government that treating gardens over 30m long as brownfield sites ripe for housing development is nothing short of irresponsible. Once again, our hopes for a sustainable future mean addressing local issues and a more pragmatic approach to the way we use our gardens.

'Growing Green: Organic Techniques for a Sustainable Future' by Jenny Hall & Iain Tolhurst is published by The Vegan Organic Network, £18.99 (0845 223 5232; www.veganorganic.net)