Seventy years after wartime Britain was told to dig for victory, thousands of plots are once again to be turned into allotments to promote national self-sufficiency.

In a project masterminded by the National Trust, some of the country’s biggest landowners have been enlisted to give up spare land for families to grow their own fruit and vegetables.

This time, however, the enemy in the war for self-sufficiency is climate change and the credit crunch rather than German U-boats.

Backers of the “grow your own” campaign, who include Tim Smit, founder of the Eden project in Cornwall, believe it will improve the nation’s health as well as cut the carbon emissions caused by food imports.

The campaign’s website goes live today. It will allow aspiring food growers to be matched with free plots in their area and with volunteers who can help them get started.

Users will be able to register their details and preferred location immediately and the “matchmaking” service will start within a fortnight.

The trust is to donate 1,000 plots from its own holdings and has pledges of donations from British Waterways, which runs the country’s canal network.

It has invoked the wartime spirit as it negotiates support from the Church of England, members of the Country Land & Business Association, the Ministry of Defence and Network Rail.

Tesco, B&Q and Suttons are providing free plants and seeds, as well as advice to growers.

“I think we’re catching the mood of the nation with this initiative,” said Fiona Reynolds, director-general of the National Trust.

“There is a tangible desire for people to reconnect with the soil. What we hope to do with this campaign is motivate people interested in growing their own food by making it really easy to get started.”

More than 15½m people in Britain are already estimated to grow some of their own food and the recession has increased demand for allotments and seeds, as families turn to the soil to cut bills.

The trust has responded by creating plots at 40 of its sites, which will become available to growers over the next three years via the campaign’s website, www.eatseasonably.co.uk.

The website directory will feature spare plots ranging from unused building land to space under advertising billboards and the tops of disused freight barges.

It will also provide templates for legal agreements that landowners can use to draw up contracts with growers. The campaign hopes most proprietors will provide the plots free in return for a share of the harvest.

For city-dwellers unfamiliar with tilling the soil, the campaign will provide an army of “veg doctors” - experienced volunteers whom growers can phone for expert advice. They will be drawn from the 390,000 members of the Royal Horticultural Society and Garden Organic, a charity.

Across the Atlantic, Michelle Obama, the first lady, has already embraced the mood by digging up a 1,100 sq ft patch of the White House lawn for vegetables.

This week, the trust will invite members of the public to apply for newly created plots at some of its most famous stately homes and estates. These will include Gibside, in Tyne and Wear, where a historic four-acre walled garden is being converted to allotments; the kitchen gardens at Kingston Lacy, Dorset; and five acres of land to be converted into 40 plots at a mill house in Wembury, Devon.

Other organisations are running similar initiatives. Network Rail is investigating plans to release tracts of disused land after a successful trial in Bristol, while parts of St James’s Park and Kensington Gardens in London, which were used for vegetable plots in the war, have already been earmarked.

In the capital, work is under way to create 2,012 plots by 2012 as part of a scheme launched by Rosie Boycott, food adviser to Boris Johnson and former editor of the Daily Express. British Waterways is planning to convert some disused barges into floating vegetable gardens.

For those unable to obtain proper allotments, veg doctors and online “grow guides” will give advice on turning window sills, terraces or urns into vegetable patches.

“We need to move away from allotments being seen as a hippie lifestyle choice to a necessity,” said Smit. “This is about our survival, in much the same way Dig For Victory was about our survival.

“Britain is committed to an 80% cut in carbon by 2050. That is a monstrous number. I don’t think it’s dawned on people what a radical change in lifestyle that represents. We need to dramatically re-evaluate the way we grow food.”

The grow your own campaign believes it may be possible to spark interest from as many as 6m people by the end of spring.

Defeating Hitler with cabbages

Dig for Victory was a government-led wartime campaign that turned gardening into a patriotic duty.

Britain imported more than 55m tons of food a year at the outbreak of the second world war, before the merchant navy carrying food shipments into Britain came under attack from German U-boats.

In 1939 Lord Woolton launched the Dig for Victory campaign, giving gardening tips and recipes, broadcast on the radio as “food flashes”, to help growers get the best from the soil.

Back gardens, football pitches and public parks were transformed into productive patches, in the effort to stave off hunger. Hyde Park even got its own pig farm.

The campaign was a huge success. Between 1939 and 1945, imports of food were halved and 1.5m allotments were supplying 10% of the nation’s food needs. Today just 250,000 allotments survive but demand for plots far outstrips supply.

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