As surely as the Fourth of July...

As surely as the Fourth of July approaches, Americans will be buying watermelons. But first, they’ll argue.

What’s the best way to pick a ripe melon? There are endless theories: Look for yellow bellies; look for green skin; count the bee stings; look for red meat; look for fresh stem ends; thump it . . . .

Actually, most of those methods have some basis in fact, but to get the final word, we went to a man who lives and breathes watermelons--Jim Zaferis of United Melon,, whose family has been in watermelons since his grandfather started growing them in the Imperial Valley in the 1920s.

“I look first at the size and shape of the melon,” he says. “Make sure there is good external color--a deep green with a high gloss. Check the stem end to make sure there is no mold or stem rot--that tells you it hasn’t been off the vine too long. Check for a yellow patch on the belly--that tells you it stayed on the vine long enough to ripen.

“But most important, thump it. Pat your belly. If it sounds that way, it’s probably overripe. You want a twang, or a ring, like a metal desk top. If you get that sound, it tells you the melon is still tight and the seeds have not begun to pull away from the seed cavity. If it sounds hollow, it’s overripe.”

Actually, Zaferis says, there is one other, even more sure-fire way to pick a perfect melon: Believe it or not, he recommends buying one that is already cut. Cut melons, if properly wrapped in plastic, will keep at least two days without losing flavor, he says. “Make sure it’s not mealy. Then the most important thing is that the flesh is deep red and the seeds are all black.”

Though watermelon growers time their planting with the Fourth of July holiday in mind, things have worked out even better than usual this year. Thanks to good spring weather, the Bakersfield area began harvesting earlier than normal and is already shipping melons to market. Combined with the normal run of Phoenix melons and the end of the Imperial Valley and Blythe harvest, prices should be very reasonable.

* Look for nectarines this weekend as well. Fantasias and Summer Grands, the two most widely grown varieties, are in the midst of their harvests.

* Grapes--especially Red Flame Seedless, Thompson Seedless and Perlettes--are plentiful as well.

VEGETABLES

* An early start is also paying off big for corn growers in the Fresno area. Last year, a cool spring resulted in a harvest that started two weeks late and forced many farmers to miss the peak Fourth of July holiday selling period. This year’s harvest started two weeks earlier than normal--a full month ahead of last year. And the crop is estimated to be as much as 20% larger than last year. The corn harvest, which begins in the Coachella Valley in early to mid-June, will continue in the Fresno area for another couple of weeks before moving into Gilroy and Watsonville and, finally, winding up in the Yakima and Wenatchee valleys of Washington in August and September.

* The California commercial tomato harvest has begun, though it won’t reach heavy production for another couple of weeks and won’t peak until October.

* Chiles from the Fresno area and the Coachella Valley are coming into full harvest too and should be reasonably priced.

GROWERS MARKETS

At the Pasadena City Hall market on Thursday afternoons, the Abundant Foods stand from Somis, in Ventura County, has beautiful summer squash: two sizes of bright golden Sunburst (the big ones are best steamed, the little ones are perfect for the grill), scaloppine and yellow zucchini, as well as five kinds of basil: sweet, anise, piccolo, lemon and purple. Everything is organically grown. Jim Walker Farms from Visalia has dead-ripe stone fruit: sweet Black Beauty and tangy Santa Rosa plums, Golden Crest peaches and truly wonderful Fantasia nectarines.