To get a sense of just how much pressure the family farm faces in the Washington region, consider Howard County, where roughly 68 families or individuals make up the core of the county's $200 million-plus farming industry.

For years, county planners have sought to preserve these farms, mostly in the western half of Howard. The county's agricultural marketing program, one of eight in the state, is devoted to helping them thrive. To boost farm sales, the state recently relaxed restrictions on which prepared foods small Maryland farms can sell to stores from their noncommercial kitchens.

Yet the number of Howard County farms fell 6 percent, to 346, while the number of acres used for farming dropped 9 percent, to 37,582, between 1997 and 2002, according to a survey released by the U.S. Department of Agriculture last year. Contributing to that decline are the tantalizing offers from housing developers, who pay as much as $40,000 for an acre for farmland these days.

Enter Community Supported Agriculture, a money-making tool widely embraced by most of the county's vegetable and fruit growers in which customers prepay an average of about $300 in a growing season for a weekly share of a farm's bounty. The farmers, or consumer-run groups, deliver to drop-off sites, arrange pickups from the farm or both.

"A lot of farmers involved with CSAs had farm stands and did the farmers markets," said Ginger S. Myers, the county's agricultural marketing specialist. "Then it became a matter of, 'How else can we tap in to the market because these stands and markets are not going to be enough?' "

Though CSAs have been around since the mid-1980s, they blossomed in recent years, partly because they help farmers plan ahead while offering shoppers freshness and, in some cases, a convenient alternative to store-bought produce.

Of the 36 CSAs within 50 miles of downtown Washington, nearly half have formed since 2000, according to LocalHarvest, an online resource for consumers. About 1,500 CSAs exist nationwide, with nearly 90 new ones entering the market each of the past five years.

Donald Buckloh, a farmland information specialist at the American Farmland Trust, a nonprofit group that promotes farmland preservation, said the concept works best for farms operating on the fringes of densely populated areas. In that setting, farms with 10- or 20-acre tracts have enough land to produce high-value crops and enough people nearby to buy them.

There is also an appealing timing element. Because customers pay upfront for their shares, farmers can use that money to cover some of their costs leading up to the harvest instead of borrowing from the bank. And customers shoulder much of the risk, said Guillermo Payet, president of LocalHarvest.

"If there's crop failure and production is half of what's expected, the buyer gets half," Payet said. "That rarely happens, and not all farmers operate that way. But that's the premise of the original CSA model."

It is a premise that lured farmer Linda Brown to take part in a Howard County CSA four years ago.

Brown and her husband, Jim, who co-own Triadelphia Lake View Farm in Glenelg, created a CSA with four other farmers, delivering two times a week to four sites.

For what breaks down to $30 a week, subscribers get a cooler full of whatever is in season as well as the occasional bouquet of flowers or loaf of bread.

"My favorite part about it is the security," Brown said. "I know I have 57 customers paying for 16 weeks of vegetables. Unlike the farmers market, I don't have to worry about giving away corn or watermelon or beans that don't sell on a rainy day. I don't have to worry about who is on vacation."

Zachariah Lester and his wife, Georgia O'Neal, launched a CSA from their eight-acre Tree and Leaf farm in Waterford, Va., charging $634 for a grocery-sized bag and $800 for three-quarters of a bushel in a 30-week stint from May through Thanksgiving.

"There are a lot of logistics that go into a CSA," said Lester, who is also a landscape gardener. "There are newsletters and recipes and administrative hassles. . . . We don't want to do too much hand-holding and overextend ourselves."

But the hand-holding helps create an emotional bond between farmer and customer that goes a long way in easing strain between the two in developing areas, said E. Keith Menchey, assistant secretary for policy at the Maryland Department of Agriculture.

"When developments build up around a farm, that's when we start to hear complaints about dust and noise and equipment from the homeowners," Menchey said. "But if [the homeowners] are connected to the farm through a CSA, it may be a way to reduce some of the tension."

David Brown picks tomatoes with his grandmother Linda Brown at her farm in Glenelg. Brown and her husband created a CSA with four other farmers.