ALASKA’S state fair, which runs until September 5th, began as a celebration among residents of the Matanuska Colony, a New Deal scheme under which 200 down-and-out midwestern farm families were moved to Alaska to see whether agriculture could gain a foothold in the coldest state. The state fair lives on, but little more than a decade after the start of the colony most of the participants had abandoned their frigid farms. The project was widely seen as a flop.

In this state, glaciers cover 300 times more acres than farms. Only 5% of the food consumed is grown locally, compared with 81% nationwide. The growing season is short and summer temperatures chilly. Tomato plants wither. Fruit trees, in most parts of the state, are just a dream.

Enter the high tunnel: a greenhouse consisting of a curved metal frame with plastic sheeting stretched across it. There is even a federal programme to pay for it. The scheme, which seeks to extend growing seasons and improve soil health, is open to farmers across the country. But it is Homer, a town of about 5,000 souls 200 miles south of Anchorage, that has become the high-tunnel capital of America, officials say. Residents have put up more than 120 federally funded greenhouses—far more per person than anywhere else.

Kyra Wagner heads the local Soil and Water Conservation District, a small-scale partner of the federal Department of Agriculture, which finances the effort. Ms Wagner has been a champion of the high-tunnel programme since it began in 2010. The structures, she explains, do not merely extend the growing season, they are “climate extenders”. “Pretty much, you’ve gone to southern California,” she says.

Only a few millimetres of plastic separate crops in the high tunnels from the great outdoors. But this is enough for Alaskan growers to produce tomatoes as well as sweetcorn, aubergines (eggplant), peaches, nectarines and kiwi fruit, and to boost production of crops by a quarter or more.

These results have brought new people to farming, sometimes accidentally. “We always liked gardening, then everything kept growing,” says Donna Rae Faulkner, owner with her husband, Don McNamara, of Oceanside Farms. Mrs Faulkner used to be a high-school biology teacher; her husband is a carpenter-turned-farmer. The couple have eight tunnels measuring 32 feet by 70 feet a few miles from Homer’s main street and grow corn, tomatoes, grapes, strawberries and leeks, among other things. They went commercial six years ago when they put up their first high tunnel. Now they harvest about 500lb (227kg) of vegetables each week.

In a place where no one blinks if you call yourself a fishermen, drill-rig roustabout, tugboat captain or gold miner, an increasing number of Alaskans are thinking of themselves as people who grow food. Since the start of the programme, the number of farms registered with the state has nearly doubled. Local restaurants have begun shaping their menus around what neighbouring farms can grow. Homer’s hospital subsidises the cost of produce boxes from nearby farms for its employees and encourages patients to buy from them.

High tunnels have sprouted on the tundra of western Alaska to Fort Yukon, a small village north of the Arctic Circle where winter temperatures dip to -40°F. And although the high-tunnel programme has not yet shifted the barometer of food independence significantly, dinner plates across Alaska are beginning to look different. Eight decades ago, the federal Matanuska Colony tried to turn farmers into Alaskans. Today, the high tunnels are turning Alaskans into farmers.