WASHINGTON (AP) – After waiting nearly 20 years to see a vegetable garden planted at the White House, Alice Waters is waiting again.

But this time it's to see how many Americans will follow the lead of first lady Michelle Obama, who last week made Waters' wish a reality when she dug a shovel into the South Lawn of 1600 Pennsylvania Avenue to make way for a garden.

"The most important thing that Michelle Obama did was to say that food comes from the land," Waters said of the garden groundbreaking. "People have not known that. They think it comes from the grocery store."

Waters, a California restaurateur who has championed local and sustainable agriculture since the 1960s, believes many health and social woes are tied to what she calls our fast food culture. Her solution? Backyard and school yard gardens that reconnect people with food at its source. Since the early 1990s Waters has sought such a garden at the White House, believing it a gesture so strong it could move people nationwide to sow their own plots.

With that gesture made, Waters is waiting to see whether seeds planted at the White House really can grow gardens nationwide. Already, California's first lady, Maria Shriver, said she will plant a food garden on the grounds of the state Capitol in May. National Gardening Association spokesman Bruce Butterfield says it's too soon to know how Americans will dig in to gardening thanks to the example set by the Obamas, but he expects it will make an impact.

"Once you tie White House to anything it has much broader reach than anything else," he says. Waters' cause also has an unlikely ally in the bad economy. As Americans embrace a new sense of frugality and self-reliance, more people have begun exploring growing and preserving some of their food.

Last year, 36 million American households grew food gardens, up 10 percent from 2007, according to the Gardening Association. That number is expected to jump by another seven million this year, a fifth of whom will be first-time gardeners.

Sales are up for gardening and food canning supplies. Same for seeds, with some companies reporting 50 percent sales growth. "This is the silver lining of this recession," Waters said in a telephone interview. "If it (the White House garden) had come earlier, it would not have resonated the way it does now."

Now, dollars and cents really resonate. Typical vegetable gardens yield about $1 of produce per square foot, says Butterfield. The average gardener will spend about $70 setting up a 600-square-foot garden.

Even people unable or unwilling to garden may be influenced. The focus on local foods may prompt non-gardeners to buy more from local farms, says Charlie Touchette, executive director of the North American Farmers Direct Marketing Association.

It's all part of what Waters calls a "delicious revolution", a rethinking of the way Americans produce and eat food.

"We are reinventing farming as a cooperative effort," she says. "We're trying really to reinvent the way we farm, the way we distribute food, the way we cook food and the way we talk about it."

For those just starting out, she urges simplicity and small steps. Check with local experts, such as an agricultural extension, to learn about what plant varieties do well in your region. And stick with items that have easy and multiple uses.

"Food has come into our conversation in America for the first time," she says. "And it's pretty awe inspiring."