Talk about good timing.

Inspired by Michael Pollan's The Omnivore's Dilemma and a handful of similar organizations in other cities, Jessie Banhazl founded Green City Growers, a Somerville, Mass., business that helps people, schools, and businesses plant and maintain gardens, in 2008. She set up shop in an urban setting, among a population with an average age of about 31. Then Michelle Obama planted her garden.

"I remember when she announced that," Banhazl, 30, recalls. "We were like, 'Ooh, this is going to be great for the business.' "

The first lady's endorsement of gardening certainly didn't hurt Green City Growers, but it was the continued growth over the next few years that would indicate that a deeper cultural shift might be afoot. In its first year, her organization helped plant 42 residential gardens in Greater Boston that yielded 3,150 pounds of food. Last year, that number ballooned to 88 gardens and 11,550 pounds of food harvested.

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But people were starting new gardens all over the country—not just in Boston. In fact, 42 million households, 17 percent more than five years ago, now grow food in home and community gardens, according to a new five-year report from the National Gardening Association. And younger Americans—Millennials, specifically—are driving the gardening revolution. The NGA found Millennial gardeners increased from 8 million in 2008 to 13 million in 2013—a 63 percent increase in five years.

Banhazl says the spike in young gardeners doesn't surprise her one bit; the average age of the farmers who work for her is 25.

“It seems like Millennials are writing their own futures because of the lack of jobs and traditional opportunities,” she says. “They seem to be a very DIY generation because of that, and they also grew up in this current boom of sustainable awareness and practices. It seems like many young people see the value of growing their own, because it just makes economic and environmental sense.”

The boom is influencing Americans of other generations too. For Eileen Gannon, tending to a box of herbs next to a sunny window of her downtown St. Louis loft was all it took to spark a decade-long obsession with growing her own food. When she moved out of her loft and into her first home on the city’s South Side, Gannon planted a bed of tomatoes before she moved in any of her belongings. A decade later and still in the same home, she’s added peppers, beans, plenty of greens and root vegetables, and her absolute favorite, tomatoes grown from heirloom seeds, to the kitchen garden she’s grown to love.

“I loved bringing friends and family gifts of crazy tomatoes they’d never seen before,” the 36-year-old says, adding that some years the Midwest heat produced so much fruit that she could can a year’s worth of barbecue and pasta sauces from her own harvest.

Gannon is among the 9 million Americans who are growing food in urban settings, a number that has jumped 29 percent in the last five years, according to the NGA survey. (A reminder to urban gardeners: Test your soil.) Furthermore, the number of Americans who report being members of a local community garden increased by an eyepopping 200 percent over the same time period.

All of these encouraging gardening trends would appear to be a direct revolt against an American diet that has become increasingly reliant on cheap, processed foodstuffs that usually travel more than 1,000 miles to get to our plates.

To what should we credit the home gardening revolution that is taking place? Banhazl thinks a handful of factors have contributed to the boom, including the first lady's advocacy around the issue and the food safety scares that started to become more visible in the news several years ago.

“A lot of people were getting sick from food produced at factory-sized operations,” Banhazl says. “People were starting to look at alternatives to that system. An obvious alternative is to grow your own food.”

Will we see a day in America when half (or more) of American households are growing food? Banhazl hopes so, not just because of how such a change would benefit her business but also because of the improvements it would bring to our nation's health and environment.

Thankfully, gardening organizations like Banhazl's are popping up in other cities, such as Portland, Ore.; Chicago; and Washington, D.C.

Some home gardeners (or would-be gardeners) definitely need a little boost to get started or a word of encouragement or instruction to keep growing. Others, like Gannon, seem propelled by deep-seated passion for the soil, and more so with the bounty that that soil generously produces season after season. Amid environmental and public health crises that require radical changes from all of us, Gannon’s passion—and that of so many a few years younger than her—is refreshing indeed.