Small figures in strange costumes shuffle in for assembly. Their bodies are completely covered and their faces masked like fencers’. Grey clouds billow up around them, setting off the school’s smoke alarms. “We must have looked like aliens,” says Olivia Greenaway, environment co-ordinator at Rosendale primary school in south London. Her pupils are dressed in borrowed bee-keeping suits, an apiarist’s first line of defence. The smoke is the second. It tricks bees into preparing to abandon a burning hive. Like many humans in times of stress, they feed rather than attack.

The Rosendale apiarists aren’t aliens, but they are from another planet.

Planet Allotment. There are about 300,000 UK members of this scrapyard community of diggers subsisting on patches of ground beside railway tracks and roads, in hidden corners of cities and on the edges of towns. Their earthy tussle with Mother Nature is celebrated from August 14 to 18, in National Allotments Week.

Rosendale’s patch is on Knight’s Hill, a few minutes’ walk from the school.

Once there, the children nibble baby spinach leaves while they dig. Most of the vegetables they grow, they eat there and then. Elderly Jamaicans give them plants and advice on how to space out their leeks correctly. They picnic on strawberries and ice-cream. They might smell sardines and potatoes cooking on a campfire. And they get to lift the lid on bee hives kept by another allotment holder.

These are rare experiences for pupils in this country, says Geoff Stokes, general secretary of the National Society of Allotments and Leisure Gardeners, which is organising the week. Mr Stokes, who married a farmer’s daughter and confesses to not liking an untidy allotment, says that the cloth-cap image of the typical holder is fading. “There are a lot more young people getting interested now and more women. Few schools are members, but we have more enquiries from teachers.” Allotments should be a community asset, he says, and local pride is essential to protect them from the developers.

Such pride is blossoming nicely in an allotment run by Scotholme primary, in Hyson Green, Nottingham. It’s an award-winning scrap of paradise tucked in between the tramline and the ring road, half a mile from the school in an inner-city area troubled with gun crime. Most of the 300 pupils are from Asian families. Many are poor and few have gardens.

Their playground is busy with football and cricket, so Angela Verity, a retired teaching assistant, created “Scotalot,” a 500 square metre organic allotment, with the help of her husband Derek. The children, staff, and parents all mucked in and, once a week, a horticulturist from Groundwork, an environmental regeneration charity, visits. It’s taken four years, but Ms Verity has realised her vision now, says Kate Hall, Scotholme’s head.

It’s a vision of grass and fruit trees, of wooden benches under willows and of raised planters full of flourishing veg. There are strawberries and blackcurrants, a bed of wild flowers, and a new pond with newts, dragonflies and a tiny, solar-powered fountain. A mobile classroom houses environmental games and a Portaloo is tactfully lost in a corner. (Half a mile is a long way to drag 30 children if one of them needs the toilet.) A polytunnel provides a tropical home for an impressive grapevine as well as courgettes, squashes, tomatoes and pumpkins, which were popular school raffle prizes last year. And there’s a bath full of forget-me-nots and geraniums and a herb garden tended by bees. “The children are dead into the herbs,” says Ms Hall. “They like to take little bits back to school with them. And they’re fascinated by the bees.”

Both Scotholme and Rosendale use such fascinations to service the national curriculum. “I’ll use the allotment anywhere there is a vague link,” says Olivia Greenaway, who has already tackled design and technology and art.

Science is the easiest subject to connect and she has rewritten her key stage 2 lessons and is working on key stage 1.

Scotholme is doing likewise. “National curriculum science is obsessed with seed dispersal and polar bears,” says Kate Hall. “On the allotment we can show them seed dispersal in action, and we can teach them about animal habitats. Seeing pond-skaters on the water makes habitats real to them in a way that reading about polar bears in the Arctic doesn’t.”

In the spring, Ms Hall brought the Year 6s down to the allotment to revise for their Sats tests. “They sat on straw bales in the cold and we talked about growth and life cycles.” Such lessons are paying off. Last year 86 per cent of Scotholme’s 11-year-olds achieved level 4, with nearly half at level 5.

Like Rosendale, Scotholme had used the allotment for art - think natural Christmas decorations - for drama, for music and, by labelling plants and equipment in French, even for languages. And of course, there’s food.

Scotalot started out as a healthy eating initiative after Angela Verity attended a meeting organised by the local primary care trust about the problems of poor diet. Rosendale’s adventure began in 2004 with Feast, a glorious combination of theatre, art and gardening that culminated in celebratory suppers on the allotment.

Nutritious food remains at the core. Scotalot cultivates heritage varieties and some unusual vegetables. As well as an annual horticultural show, the school holds its own apple festival in October. “It’s not surprising if children don’t like apples when all they’ve tried is Granny Smith’s which break your teeth,” says Kate Hall. “So we get them to try different apples, and apple juice and apple crumble.”

Allotments cost money, so Angela Verity has developed financial green fingers, raising pound;75,000 in four years. Scotalot is financially self-sufficient and well equipped. There’s a class set of boots and cagoules, as well as all the gardening kit. The locally-made Douglas Fir benches cost pound;250 each and Scotalot has bought a generator and a heater so pupils can work all year round.

Was it worth it? “The knowledge the children have got is incredible,” says Ms Verity. “And it’s an oasis.” Olivia Greenaway agrees: “There’s a sense of community and it’s beautiful and calm, a real escape.” Rosendale now grows some fruit and veg in its own grounds. When the school won a greenhouse, some people felt the allotment had become superfluous. But Ms Greenaway replied that they didn’t understand the magic. “So they took their kids up there and then they got it.”

National Society of Allotments and Leisure Gardeners: www.nsalg.org.ukOther green-fingered organisations include:Groundwork, environmental regeneration charity: www.groundwork.org.ukThe Government’s Growing Schools initiative: www.teachernet.gov.ukgrowingschoolsOrganic Gardens for Schools: organicgardening.org.ukschools_organic_networkThe Royal Horticultural Society school members: www.rhs.org.uklearningeducationschoolscheme.aspLearning through Landscapes, the school grounds charity: www.ltl.org.uk