Since the beginning of her husband's term in office, Michelle Obama has made healthy eating her ethos. She hopes it will change things in the country, where an estimated one in three children is obese.
When the season changes and the trees have dropped their leaves, it's easy to see the garden on the south side of the White House. It's easy to imagine that what grows there ultimately lands on the presidential plate.
Michelle Obama got busy working on the garden only two months after the Obamas moved into the White House.
For the first time since World War II, the president's home would have its own proper vegetable garden. And it would be more than just a herb garden like the one started in the 1970s, when Jimmy Carter was president, or a mini-garden like the one President Bill Clinton had in the 1990s.
Obama got help from 23 schoolchildren on the first day of spring in 2009 when she grabbed her shovel. Initially, she worried whether it was a good idea, the first lady said in her garden book American Grown: The Story of the White House Kitchen Garden and Gardens Across America, which came out a few months ago.
She wasn't even sure whether they were allowed to plant a garden on land that belongs to the National Park Service, she wrote, and she didn't know whether the soil in the middle of Washington, DC was fertile and received enough sunlight.
As it turned out, sometimes torrential rain threatened the plants the most. Obama was able to solve that problem by putting down a protective layer of straw.
Depending on the season, all kinds of food grows in the garden only a few metres from the Oval Office: from peas, spinach and broccoli to red potatoes and four types of lettuce and rhubarb.
The garden produces more than 330 kilograms of vegetables per year, according to an official estimate. Much of it is served at the White House, with some going to the first lady's family and some being served to state guests.
Sam Kass, the president's cook, said on CNN that he goes into the garden almost every evening to pick something. Food that isn't eaten at the White House goes to a charity that gives it away to people who need it.
The garden is more of a hobby than anything else, but Obama would also like it to act as a reminder to young Americans to eat healthy food.
"It is definitely a passion - getting our kids in this country eating healthy, helping families make good choices about how they eat and staying active," Obama told ABC television in an interview that aired after her book came out.
American children face an epidemic of obesity, according to numerous studies and warnings. Her garden is meant to help blunt that and start a debate about how healthy eating habits can have a good affect on children.
"What we know we need to do is give parents, communities, families the tools and the information they need to make choices that are right for them, and there's no one-size-fits-all solution," she said on ABC.