At the peak of spring olallieberry season, Ken Hagan estimates that he gets 2,000 people a day visiting his Brentwood family farm, Bacchini's Fruit Tree, to pick the fresh berries.

It's become a bit of a California tradition to go olallie picking in June, when the tangy fruit is ripening on the bush.

"They're very easy to pick and very tender," Hagan says.

Bakers say the berry's tart and slightly sweet flavor make it a perfect filling for pies, cobblers, muffins and cakes.

The olallieberry, a cross between a blackberry, loganberry and youngberry, originated in 1949 in Oregon, but mostly thrives in California -- especially on the coast. The olallie, a Native American word meaning blackberry, likes plenty of rain and mild temperatures. And with this year's torrential downpour, growers are expecting a bumper crop.

Olallies, like most other spring and summer crops, are late this year, and just starting to show up in markets.

Hagan says that because of his inland location, his olallieberries came in earlier than most and will only last until late June. He suggests that pickers wear comfortable shoes and get to the farm, located at 2010 Walnut Blvd., by 8 a.m. Bacchini's is open for picking Friday through Sunday. For more information, check Bacchini's Web site at brentwoodfruit.com.

Farms near the ocean, like Swanton Berry Farm-owned Coastways Ranch on Highway 1, 30 miles south of Half Moon Bay, don't expect berries to be ready for public picking until sometime after next week (831-469-8804). The coastal olallieberry season usually lasts about six weeks.

Webb Ranch Farm in Portola Valley has already begun selling its olallies at its farm stand at 2720 Alpine Road, off Highway 280 (www.webbranchfarm.com). Hours are from 10 a.m. to 6 p.m. daily (650-854-3134).

The Webb family, which owns and operates the stand, expects the olallieberry season to last until mid-July. They are in the process of going organic and don't use any pesticides on their berries.

When the berries are ripe, they're sweet enough to eat straight. But Hagan's wife, Sheila, likes to whip out the Bacchini family's favorite recipe -- a twist on classic strawberry shortcake.

"People get tired of pies," Hagan confesses.

Sheila Bacchini-Hagan fills her homemade shortcake biscuits with an olallieberry compote that she makes with a mixture of balsamic vinegar, lemon juice, red wine, spices and sugar. Then she tops the confections with a generous dollop of whipped cream.

She also uses olallieberries to make a dipping sauce to pour over savory meats, fish and poultry (see accompanying recipes). While olallies have a distinctive flavor, it's fine to substitute blackberries when cooking or baking.

At San Luis Obispo's Avila Valley Barn, a U-pick farm, produce stand and specialty shop, located at 560 Avila Beach Drive (805-595-2810), owners are already developing an olallieberry ice cream to sell in their new creamery. Debbie Smith, a managing partner, says they are also trying to create an olallieberry drink -- a combination of lemonade and olallieberry juice.

Smith says they have about 8 acres planted in olallies. "And the crop looks absolutely beautiful," she says.

On weekends, families are transported to the berry patch during a complimentary hay ride. There, they can harvest as many olallieberries as they can carry in boxes and baskets that are provided by the farm. Inside the Avila Valley Barn store, open from 9 a.m. to 6 p.m. daily, are freshly baked olallieberry turnovers and lattice pies. The barn also sells olallie jams, jellies, vinegar and mixes for cobbler. Smith is a particular fan of the olallieberry crumble, a simple, old-fashioned, buttery comfort food that brims with juicy berries.

North of San Luis Obispo, in the coastal town of Cambria, the owners of Linn's Fruit Bin are preparing to freeze more than 50 tons of olallieberries from this season's crop. They will use the berries during the next year to make their signature desserts, which they ship all over the country (linnsfruitbin.com).

John Linn and his wife, Renee, started farming in 1976. Soon after they opened a farm stand and began selling their homemade olallieberry pies. At the time, the berry was barely known. But it soon became the "cornerstone" of their business, says John Linn. Wife Renee began experimenting with the berries, eventually developing recipes for olallie muffins, cheesecakes, syrups, curd, vinegar and chutney.

"It's become a tradition for which we've become widely known," says John Linn. "Not bad for a berry that's grown on only about 100 acres in the entire state."