Few things symbolise how profound the change of tenancy at the White House has been than the digging of a garden. Last month, the Obamas tore up 1,100sqft of presidential lawn to create an organic community garden, a "Victory Garden" - named after America's wartime equivalent of Britain's Dig For Victory campaign. On an ostentatiously unpresidential budget of $200, they prepared the soil of the South Lawn for planting with the help of a local junior school. The crop will be shared between the White House and Miriam's Kitchen, an initiative that feeds Washington's homeless.

"We've been talking about it since the day we moved in," said Michelle Obama, as she dug into the sod before the cameras. Which was true. She's been mentioning the garden at every opportunity, telling Oprah's Magazine a few weeks earlier: "We want to use it as a point of education, to talk about health and how delicious it is to eat fresh food, and how you can take that food and make it part of a healthy diet. You know, the tomato that's from your garden tastes very different from one that isn't."

Michelle Obama and the President understood that the Victory Garden is rich in metaphor, the perfect way for the administration to demonstrate that America is turning over a new leaf. And over the next few weeks she'll be planting oakleaf lettuces, fennel, shallots, peas, carrots, onions, rhubarb, chard, kale and collards, and a herb garden, as well as installing two beehives alongside paths fringed with nasturtiums and marigolds. That the First Lady, rake in hand, shouting, "Let's hear it for vegetables" could count as a positive press opportunity suggests something has changed deep in the American psyche.

This hasn't materialised out of nowhere. The American presidency is riding on the back of a grassroots movement which has been growing throughout the decade. In Britain and in America, people are turning urban spaces and parklands into places that produce food. Rosie Boycott, Boris Johnson's chair of London Food, is promising to create 2,012 new, mini urban farms by 2012. Even the venerable National Trust is committed to turning land all over the UK into 1,000 new allotments.

Obama's idea for the Victory Garden was prompted by an article in the New York Times last October by food activist and academic Michael Pollan. In "An Open Letter to the Farmer In Chief", Pollan advised Obama that when he entered the White House he should "tear out five prime acres of lawn and plant in their place an organic fruit and vegetable garden". Pollan continued, "The President should throw his support behind a new Victory Garden movement." Three days later, Obama was quoting the article at press conferences. Tear up the front lawn. Plant your own Victory Garden.

"Maybe we were part of that," says San Francisco artist Amy Franceschini, smiling. "I'm not going to lay claim to it."

Franceschini is the originator of what was, until the Obamas' allotment, the most famous of a new generation of Victory Gardens - planted bang in front of San Francisco's City Hall. For four glorious months last summer, community groups planted and harvested vegetables, distributing the hundreds of pounds of produce they grew to local food shelters.

Franceschini is the daughter of two farmers. Her father was a "big-time industrial farmer, 6,000 acres, with pesticides", but after her parents divorced, Amy lived with her mother, who was a passionate organic farmer. Amy became an artist, but showed she was still a land girl at heart when she named the arts collective she founded in the 1990s Futurefarmers. Most of her work in those early days was digitally based. Like many people living in northern California at the time, she was interested in the way computers could connect people to create new communities.

Read the rest of the article here.

Photographs. Top: Edible Estates 2 by Fritz Haeg, Lakewood, California, 2006. Below, Victory Gardens, San Francisco 2008, by Guerilla Futures | Jason Tester