Updated

A growing army of needy people and volunteers are descending on farms, fields and backyards across the nation in search of leftover produce that might otherwise go to waste.

The tradition known as gleaning has gone on for centuries, but pickers and organizers say the stakes are higher these days as families struggle against the recession and try to maintain healthy diets amid a national epidemic of obesity.

"I feel like I'm doing something for myself and for people who need it, like me," volunteer Samuel Negrete said as he searched for the last pieces of fruit in a citrus orchard in Riverside County.

Negrete, 43, lost his job at a home improvement store six months ago and is struggling to support his family of four children.

"When I'm home, I'm thinking about all my problems," he said. "But here, my mind is clear."

Negrete was among a group of about a dozen volunteers clambering up citrus trees in the tiny grove where the smell of orange blossoms filled the air.

The local gleaning program was started by Salvation Army staffer Maddy Graham to supplement food boxes given to needy families who too often rely on fast food and discount retailers for high-fat, high-sugar foods that can lead to health problems.

The volunteer pickers get financial assistance and a box of oranges in exchange for working once a week.

Negrete said his kids devour the oranges.

"When they're sweet like this, they're better than candy. And better for their teeth," he said in Spanish, wiping sweat from his forehead.

Elsewhere, the Society of St. Andrew, a national gleaning organization, recruits volunteers from churches, scout troops and schools to pick sweet corn in Florida, collards in South Carolina, potatoes in Colorado and apples in the Blue Ridge Mountains of North Carolina.

"Fresh produce is expensive and it spoils quickly," spokeswoman Carol Breitinger said. "But fresh fruits and vegetables are essential to people's diets."

The pantries of many food giveaway programs are stocked with packaged goods and caloric filler foods such as pasta because those products are cheap and easy to ship and store, she said.

Meanwhile, perfectly good produce that could balance those offerings sometimes rots in fields because of cosmetic flaws or high shipping costs.

"I can remember going into a cabbage field on the eastern shore of Virginia to pick after the harvest," Breitinger recalled. "There were thousands and thousands of pounds of perfectly good cabbage."

Gleaners step in when community-minded farmers give them the run of their fields after crews of paid pickers have already passed through, or when cosmetic damage caused by pests or weather makes harvesting and shipping the produce a money-losing proposition.

In exchange, farmers get a tax credit and the satisfaction of knowing their hard work didn't go to waste.

In Riverside County, where subdivisions have sprouted in former citrus groves, the need for free food has jumped as nearly 80,000 people lost their jobs in the past year.

Demand doubled in a single month at the Salvation Army, Graham said.

Even when struggling families stretch their dollars with food stamps and careful shopping, the produce aisle is often beyond their budgets, she said.

As a result, food banks are evolving into nutrition banks, said Willy Elliott-McCrea, who runs the Santa Cruz Second Harvest Food Bank.

Fresh fruits and vegetables now represent 60 percent of the 6.5 million pounds of food the Watsonville, Calif., organization distributes every year.

Most of that produce is donated by generous growers and distributors. But a lot more is left to rot in fields.

"Probably a hundred times more food could be gleaned if there was the people power to do it," said Elliott-McCrea, who helped found Ag Against Hunger, a Salinas Valley group that ships donated fresh produce to food banks along the West Coast.

Farmers in the valley allow volunteers to pick crops on short notice every weekend for food banks, said Abby Taylor-Silva, executive director of Ag Against Hunger.

"A grower would call us because a crop has sun damage or pest damage, and it's still good product but not good enough for market," she said.

Still, the gleaning program provides only one percent of the fresh produce that Ag Against Hunger distributes, she said. Most donations come already picked, when market prices dip and make shipping a losing proposition for farmers.

Gleaning is also increasing in cities and suburbs among people moved by the sight of wasted fruit from backyard trees and gardeners who plant extra leafy greens to donate to soup kitchens.

Those efforts also promote healthy diets, Elliott-McCrea said.

"If you have high school kids going out and picking their neighbor's apple tree, they'll have a different relationship with those apples," be more likely to eat right and donate to the needy in tough times, he said.

In the tiny grove in Riverside, pickers enjoy the camaraderie of making a contribution.

Betty Mairena tugged on a long picking pole and improvised a song:

"Little orange, so golden! You're going home with me where I'll make a delicious juice out of you," she cooed in Spanish as flower petals fell in her hair.