The Geans grow Gaviota and Seascape strawberries, known for sweetness and flavor but not for productivity or the ability to survive shipping and days in a supermarket produce department. Until five years ago, the only place to find Harry’s Berries was at Southern California farmers’ markets — and today, the markets still make up 70 percent of the farm’s sales.

The berries are grown organically, despite initial skepticism from Mrs. Gean’s father, who founded the farm and swore that the unconventional approach wouldn’t work. And each section of the field is harvested only once every five days, to give the fruit enough time to reach its flavorful peak. Large-scale growers typically pick every three days.

Ripeness is all: When the berries run out, they run out, because the Geans would rather send a customer home empty-handed than with a berry that doesn’t meet their standards. That accounts for the lines that form an hour before the area’s biggest market, in Santa Monica, opens for business.

The farm, which this year celebrates its 50th anniversary and more than 30 years at the markets, has been a shrine for generations of berry lovers, both professional chefs and customers who ate their first berry as toddlers and now push strollers of their own. Bucking tradition has worked out well: Last year, the Geans sold 500,000 pounds of strawberries.

Perfection doesn’t come cheap — a pint costs $8 — but the lines are long even when berries are plentiful, as they are now at the start of the peak season.

Nancy Silverton, the award-winning Los Angeles chef and author who owns the Mozza restaurant group with Mario Batali and Joe Bastianich, has been buying Harry’s berries since she tasted her first one in 1989. Jeremy Fox, the executive chef at Rustic Canyon restaurant in Santa Monica and the author of “On Vegetables,” won’t use anything else.

Mr. Fox sometimes identifies the berry’s provenance on the menu, for a dish like the strawberry Pavlova with yogurt and black pepper. Ms. Silverton, on the other hand, assumes that by now most of her customers know exactly where the berries come from.

Their East Coast counterparts, from Philadelphia to Boston, jockey for an allotment from a far smaller shipped harvest. They have included the New York restaurants Wildair, Upland and Le Bernardin; a few retailers — like Eataly, owned by Mr. Batali and Mr. Bastianich; the online grocer FreshDirect; and the Doughnut Plant, which features strawberry-forward doughnuts in the spring.

Ms. Silverton and Mr. Fox rhapsodized about the fuller, sweeter berry taste, the juice-dribbling texture (compared with the chalky innards of some commercial berries) and an aroma that wafts toward marketgoers before they reach the stall. When they ran out of superlatives, they both settled on a single adjective: “red,” summing up all a strawberry should be.

The farm didn’t start out this way. In 1967, Mrs. Gean’s father, Harry Iwamoto, a Japanese immigrant, leased 120 acres in Oxnard and planted what the Geans refer to as “commodity” berries, a hardy strain picked when they are still partly white inside, to extend their shelf life. They didn’t taste like fully ripe berries, but that was beside the point. They made it to the grocery store intact.

Mrs. Gean grew up on that farm, and married Mr. Gean, her high school sweetheart. In 1986, she was running a Harry’s Berries roadside stand and he was driving a beer truck when they heard about a new farmers’ market in nearby Ventura. They drove out to take a look.

Mr. Gean was smitten. “I’m quitting my job,” he said, ready to trade his truck route for the chance to develop an offshoot of the family business: working the farmers’ markets, where they could meet customers and cut out the wholesale middleman.

Mrs. Gean, though similarly tempted, suggested they might want to try it first. They started at two markets, added three more, and applied for a stall at the biggest, oldest market in Southern California, the Wednesday market in Santa Monica. Then they waited. A year. Two.

When they finally secured a slot, Mr. Gean announced again that he wanted to quit. “I saw it as an upgrade,” he said of swapping beer for berries. “Nobody ever got in a car accident from eating too many strawberries.” This time, his wife agreed.

At first, they sold the same commercial berries they had always grown. But in 1993, the farm lost its lease to a water conservation project, and the family stood at a fork in the road: They could find another large parcel to sustain their wholesale operation, or they could downsize and become farmers’ market purveyors, period.

They went small, in fairly drastic fashion — leasing a 20-acre plot across the road from the original farm, planting new strains and abandoning the wholesale business. As their market business grew, they leased an adjacent 27 acres, and in 2008 bought a 10-acre parcel.

The Geans now send trucks to 19 markets, seven days a week. They coax strawberries out of the ground year-round, thanks to the mild climate, which enables them to create a labor force as unusual as their produce. Many of the Geans’ pickers have worked the farm full time for 20 years, freed from the need to follow seasonal crops.

“We stepped off the traditional success track at a fortuitous moment,” Mrs. Gean said. “The farmers’ markets enabled us to become what we are, to make a profit.”

That was the retooled business model until T. J. Murphy, chief executive of the East Coast wholesaler Baldor Specialty Foods, found himself stranded on the West Coast because of a snowstorm back home. He decided to check out the Santa Monica farmers’ market he’d heard so much about, tasted Harry’s berries, and contacted the Geans to say, “I have to have those berries.”

They told him it wouldn’t work — berries as ripe as theirs would never survive shipping — but Mr. Murphy persisted. “I’ll have my truck there,” he recalled telling them. “Just give my guy berries, and I’ll pay for them no matter what.” All the Geans had to do was build a new cooler that chills the berries more quickly, and pack them in sturdy plastic clamshell containers.

“The truck pulls in, they load up the berries, the truck pulls out,” Mr. Gean said. The fruit arrives in East Coast restaurant kitchens and on market shelves within 36 to 48 hours of being picked.

In 2012, they shipped about two dozen 80-pound flats twice a week. This season, at peak volume, Baldor will distribute as many as 860 flats every week.

This is big enough, by Mrs. Gean’s measure: Gaviotas and Seascapes alongside two new Spanish varieties, a one-acre patch of even more delicate French berries called Mara des Bois, tomatoes, green beans and products made from anything that comes back from the market unsold, including tomato salsa, fruit jam and pickled beans. Harry’s Berries, she says, is done expanding.

Three generations live on the property — the Geans in a house they built out of metal shipping containers, along with their three grown children, who work the markets; their spouses; and seven grandchildren, ages 20 years down to 5 months. Mrs. Gean makes dinner for 15 every Tuesday night, when dessert could be strawberry pie from a family recipe, or Ms. Silverton’s strawberry shortcake, or strawberry ice cream produced in a barter arrangement with a local producer.

The farm itself is as good as Disneyland as far as Mrs. Gean, 60, is concerned. Mr. Gean, 63, creates oversize junk-art sculptures that are scattered around the property, and they have installed a party room, outdoor dance floor, aboveground swimming pool, swing set, trampoline and playhouse.

A framed set of old photographs hangs on the exterior wall of a small, one-story office — of Mr. Iwamoto, who died in 1993, just as the new farm was taking shape, and his wife, Yayoi, who died in January. Mrs. Gean’s next project is a Japanese tea garden to honor her parents, which she describes to her grandchildren as “sort of a museum of your great-grandparents.”

“Someone will continue,” she said, imagining Harry’s Berries as a fourth-generation farm someday. “Because it’s not just a farm. It’s a family tradition.”