Buckets of fun: At a pioneering Dorset primary school children learn first-hand how to grow and market their own food

School gardens have been enjoying a renaissance thanks to initiatives such as Learning through Landscape and Food for Life. But there has always been an in-built difficulty – the long summer holiday. In Dorset, Powerstock Primary School seems to have the answer: shiny, zinc buckets. There are 60 pupils at the school and they all have their own buckets, planted with an eclectic mix of flowers, herbs and vegetables. When summer term ends, the children take their buckets home. They see their sunflowers bloom, their lettuces fatten up. The whole exercise has point, which it can scarcely have if you never see the end result of your labour.

The buckets are lined up against the stone walls of the school entrance where the children see them every day. At break time, Ruby (8) was checking her carrots, Edward (5) his sunflower. Behind the school, away from the tarmac playground, each class has a raised bed, where they grow food. Some is served up at school lunches. Some is harvested and sold at the school's Wednesday market.

But for all this to happen, you need catalysts – a head who sees the benefits, teachers who are prepared to stitch gardening into the dreaded national curriculum, and parents who will pitch in to help: building raised beds, fund raising (the PTA bought the buckets). At Powerstock, the head Claire Briden runs a cooking club for the older children at the school and welcomes the opportunity the children have to grow some of the things they cook. "It makes those important links between growing and eating," she explains, "the links that can so easily be forgotten. It also involves the families. When those buckets go home for the summer, the message spreads." Mrs Briden leaves the school this summer, but has made sure the club continues under the magnificent Heather Pitcher, whose cooking is a local legend.

Food seems to drive much of the gardening at Powerstock school and teacher Anna Seal explained why. The Food for Life initiative sets high targets for the food children eat at school: 75 per cent unprocessed, 50 per cent local and 30 per cent organic. The Food for Life messages – quality, provenance, sustainability – need to be embedded in the way the children are taught. By making and looking after gardens, they themselves become part of lessons on geography and the use of land. It's an obvious way into science and how things grow. Drake (5) gave me a very succinct lesson about what roots do.

Anna Seal, a great gardener herself, sees other benefits too, less easy to quantify, but important. The children garden in small groups of five or six at a time; they need to learn how to cooperate. And they become aware that if these things they've brought into being aren't looked after, they may die. It teaches responsibility. It's also a settling kind of activity, she feels. It's a calming thing to do. And it's outside. "A polytunnel would be fantastic. Then we could garden rain or shine."

Anna Best has two children at the school, six-year-old twins Lucy and Alice. She and Christine Endicott, the mother of Jack, who is in the reception class, are committed gardeners themselves and are both involved in the school's garden and its market stall. "Parents bring in surplus produce – eggs and things – and last week we were selling bags of salad the children had harvested from their own gardens. But, given a bit of back-up, the children could run the market stall themselves."

I suppose, if I were looking again for a school for our three children, it still wouldn't be the first question I asked. Has this school got a garden? I'd still be looking, as I was at the time, for an atmosphere, a feeling, a general impression that this is a pleasing place to be. Powerstock has got that in spadefuls. It's an old school, built in 1848 with stone carted from a church demolished at neighbouring West Milton. Consequently, it feels rooted, comfortable in its space. It's solid and well-made with a lovely high perpendicular window bringing masses of light into the interior.

As a parent, when I'd clocked the inside – the computers, the artwork hanging everywhere (especially the pictures the children had drawn of wild flowers) – then I would take in the outside: the willow house, the raised beds, the wildlife patch, where, the morning I was there, the children of Years 1 and 2 found a frog. For several years, it seemed that wildlife was the only reason to have a school garden. I'm glad that the view now has broadened out and particularly glad that, here at least, growing food is such an important part of what the children do.

Once, it was taken for granted that gardening, cooking, sewing and carpentry would be part of what pupils learnt at school. Madeline Agar's 1909 Primer of School Gardening was a best-seller at the time, packed with practical information about setting up plots (no bigger than 6ft x 10ft she sensibly advised), the costs involved and the best crops to grow. Children, she wrote, must inevitably be "braced and refreshed by the quiet, simple, breezy activity". The language and ethos may be archaic, but essentially that's what Anna Seal is saying. It's good for children to be outside, physically engaged with the soil and its mysteries.

Even in the Sixties, designs for school gardens were still being drawn up. At the new Sir Edmund Hillary Primary School in Worksop, planners envisaged a rockery, a rose bed, a herbaceous border, as well as a large area of bedding-out. Nobody thought to include vegetables, though there's a terrifyingly long screen of Cupressus 'Green Hedger'. It's a period piece. But already then, gardening as a subject was morphing into rural studies or environmental studies and was moving a long way from the actual activity of growing things. It's no wonder that among this generation, now grown-up, there's been a rush for allotments. They missed out on what Eleanor and Jack and Katy are learning in primary schools like Powerstock's. And I'm glad to know about their market. Next time I run out of salad, I'll know where to go.