On a frost-dappled October morning, Jerry Dillon scoops a handful of green beans onto the scale. He adds more, then plucks a few off, waiting for the pointer to settle on the red line taped to the scale at the one-pound mark. Dillon, 36, like the other workers at the Red Wiggler Foundation farm in Clarksburg that day, is mentally disabled.

"Nineteen. I did 19 bags," he shouts, running out of the barn to share the news with his fellow farmers.

They don't linger too long over their friend's achievement. A heavy frost is predicted that night, and the growers--as the workers are called--rush to pick the remaining green tomatoes, heaping them into bushel baskets.

The farm offers people with developmental disabilities the opportunity to gain horticultural skills and earn money and is one of the few of its kind in Maryland and Virginia. Crops are sold at a farmers market and directly to county residents.

Woody Woodroof, 34, who founded the farm in 1996, had served as a job coach for people with mental disabilities and as a residential counselor.

"I was unhappy with the breadth of choices available to the people I worked with and decided to come up with my own solution," he said. "What we've done here is transfer the focus from the disability to the ability of what they can do."

For example, Debbie Burnstein, 44, of Silver Spring, used to stuff envelopes inside a windowless warehouse. But many days she would refuse to work, agitated at being inside all day.

At the farm, she grows zinnias and other flowers and collects eggs from the chicken coop.

"Out here she's just a wonderful worker. Choice is a big thing here. There are a lot of different tasks. It's also quiet and pretty and calm, all the things Debbie didn't have at her last job," said Barbara Hittle, a job coach with Arc of Montgomery County, which provides vocational training, group homes and apartments, and other services for people with mental disabilities and their families.

Workers from Arc are paid a minimal wage based on federal regulations and spend five hours each weekday at the farm. During the winter, the workers have jobs such as putting together boxes that are arranged by Arc.

In addition to growers from Arc, people with developmental disabilities in county public and private schools also are employed by the farm. Volunteers, recruited by an AmeriCorps coordinator, help with chores too difficult for those with disabilities.

Woodroof tailors the jobs for the workers, who have a range of abilities. For example, planting watermelons is easier than most flowers because the seeds are much larger.

For Dillon, of Bethesda, that has made all the difference; he now holds watermelons in such high esteem that he got business cards that read "watermelon grower" as his title and hands them out to everyone he meets.

On Tuesdays, from spring through fall, Dillon sells watermelons and some of the farm's 100 other crops at a farmers market at the National Institutes of Health in Bethesda. In addition, the farm provides produce for 37 Montgomery County households in its community-supported agricultural program. Families pay a set price at the beginning of the season for a weekly box of fruit and vegetables from Red Wiggler and neighboring farms.

Last year, the farm grossed $20,000 in sales. Since it opened, it also has donated more than 7,000 pounds of surplus produce to the Manna Food Center in Rockville.

On a recent morning, workers bagged chestnuts gathered from trees next to the barn. They also packed peppers, winter squash, eggplant, chard and other vegetables for the agriculture customers. The weather offered a contrast to the relentless heat of the summer, when growers could work under the pounding sun only for brief periods.

It's not always easy, Peter Monahan, 50, of Silver Spring, a participant in the Arc program, readily acknowledged.

"It's a hard job. It's a dirty job," he said of his work feeding chickens and growing tomatoes and squash. "Mostly I like it."

The farm weathered the drought because of the variety of crops planted, so that while some failed, others thrived. Woodroof finds a lesson there that goes beyond the farm.

"Our belief in diversity in the field links to our belief in the diversity of humans," he said. "There is no one right way to do things, no one crop that's perfect. Everyone has a part to play."

For more information on the vocational programs with Arc of Montgomery County, call 301-294-6840.