They're about to throw out the first tomatoes of the season.

The first heirloom tomatoes, that is.

Saturday, May 5, is the opening day for Chester County's farmers' market season, starting in West Chester.

The West Chester Growers Market will reopen for business from 9 a.m. to 1 p.m. Saturday at the usual spot, the municipal parking lot at Church and Chestnut Streets.

The following Tuesday, the Oxford Village Farm Market will take its turn, from 2 to 6 p.m. at Third and Locust Streets in Oxford.

Paul Hauser, manager of the West Chester market, has a farm and greenhouse in the village of Lincoln University, where he grows those heirloom tomatoes as well as berries, tree fruit and vegetables. He is one of more than 20 vendors at West Chester.

Hauser says the market uses growers in its name because when it started, about 14 years ago, it saw that many of the people selling at farmers' markets were anything but farmers.

He says "If you don't grow it, you don't sell it" is the mantra at West Chester. They do make exceptions, though - for bakers. That one goes, "If you don't bake it, you don't sell it."

There will be four bakers at the market, along with the farmers/growers. New this season, he says, will be a vendor selling peppers and one who bakes and sells dog biscuits and puppy treats.

In Oxford, April Ennis-Pierson, who runs the farm market there and is also the town's Main Street manager, says her market will start with seven or eight vendors, adding more as the season progresses.

She says the market reflects the character of the Oxford area, which is still fairly rural, with Amish farm families who sell fresh-from-the-field produce and homemade baked goods.

Other markets will be opening soon, including Phoenixville and Kennett Square on May 18. The Chester County Agricultural Development Council has just published a map that lists farmers' and growers' markets, farm stands, and community-supported agriculture or cooperative farms in the county.

It counts seven markets in all. The others - Eagleview, New Garden and West Grove - will open later this month.

The map is available in public libraries; most county offices, including the commissioners' offices; and the government services center. You also may request a copy by calling 610-344-6285.- Bill Raftery