The 62-year-old, who gardens after his workday ends at his state highway job, is one of a growing number of Americans rolling up their sleeves and digging into the dirt to raise crops or livestock on a small scale.
The produce and meat raised by these small farms, sometimes called "hobby" or "lifestyle" farms, provides much of the food found at the nation's farmers' markets and roadside stands, said Maria I. Marshall, an associate professor of agricultural economics at Purdue University. Many of the farms raise specialized crops and practice organic or sustainable farming.
Mithoefer, who sells whatever produce his family doesn't eat, freeze or can at a Saturday farmer's market, said he loves working outdoors with a nephew who helps him till, plant, weed and harvest plots covering about a half-acre just east of Indianapolis along U.S. 40, the famed National Road.
The Greenfield, Ind., resident recently sat in the fall sunshine near his fields vigorously washing buckets of cucumbers, squash, turnips and beets for the farmer's market as the air hummed with the din of cicadas and crickets.
"We do it for the enjoyment," Mithoefer said as he scrubbed dirt from a cucumber.
"We make some on it _ it doesn't lose money. We try to be reasonable with our prices and give the customer a good quality product for a reasonable price. Not much goes to waste."
The U.S. Department of Agriculture's most recent farm census shows that while the nation's largest farms keep getting larger, a growing number of small farms also are sprouting across the nation.
February's census report found that the number of farms under 50 acres soared nearly 15 percent between 2002 and 2007 to about 853,000 nationwide. Farms under 10 acres grew even more, with their numbers rising about 30 percent to 232,000.
Nearly 300,000 new farms began production since the last census in 2002, and they tended to have fewer acres, lower sales and younger operators who also work off-farm, said Ginger Harris, a demographer with National Agricultural Statistics Service, a branch of the USDA.
Although the census numbers show a growing interest in small farms, she said farmers weren't asked their motives for starting their farms or why farming isn't their primary occupation.
"We don't know if they do something else because they can't make enough money with their farms, and they would like to be a full-time farmer, or it really is just a hobby," Harris said.
Denise Beno Anderson started her 5-acre chicken and vegetable farm in central Ohio in 2003 with her husband. They divorced this year, and Anderson now runs the operation with the help of a cousin and her 17-year-old son, Peter, who works as a farmhand.
Anderson said she moved from Columbus, Ohio, about an hour to the south, to the small town of Mount Gilead in part because she wanted to start a farm like the one she grew up on.
"I had my taste of the city, and I got tired of the sirens and the helicopters and the traffic and the smells, and I felt more comfortable in a rural setting," she said. "I had to get back out to my rural roots."
Anderson, 46, raises about 500 chickens from six old-fashioned layer chicken breeds, including Barred Plymouth Rocks, Rhode Island Reds and Americanas, which lay green eggs. She also raises vegetables and a few hogs, lambs and rabbits _ all without chemicals, antibiotics or hormones.
Her farm has about 50 customers who pay for regular allotments of either eggs and vegetables or eggs and selected meats _ or both. Anderson also sells vegetables and meats twice a week at two Columbus-area farmer's markets and to retail stores.
She also works part-time as atrail ride guide at a local horse stable.
"I can pay the mortgage on the farm, the utilities and other things," Anderson said. "We're not living a life of luxury over here, but we're not on food stamps, either. We're able to make a living."
Mithoefer, who grows his crops on a tiny slice of an 85-acre grain farm owned by his mother and two cousins, started farming as a child. In the 1970s, he took over some of the vegetable fields his maternal grandparents had tended for decades at their farm.
Mithoefer estimates he sells between $1,000 and $1,500 worth of vegetables each year at a local farmer's market. When he retires, he plans to keep his current fields but plant a wider variety of crops to extend his harvest, which now runs from June through November.
He hopes his nephew, who's 25 and wasn't even 10 when he started helping him with the fields, will take over someday.
"He's one of the reasons I'm still at it _ because he still wanted to do it," Mithoefer said.