Plus, according to the USDA, watermelon is fat-free and a good source of vitamins A, B6, C and thiamin.

But picking a ripe melon can be tricky. If only you could taste it before buying.

"I love watermelon, and I taste away when I'm shopping for it," says Jimmy Iovine of Iovine Brothers Produce in the Reading Terminal Market.

He's been selling watermelons from Florida and Georgia lately, but the Jersey crop should be in this week, he says.

"Melons are a desert fruit," Iovine says. "They like it dry. And from what I'm hearing, the local melons will be good this year."

A ripe melon will be dark and even in color, as well as heavy for its size. Compare several of the same size for heft, which is an indication of juiciness.

But don't drop it. Watermelon can be bruised inside even if it doesn't crack.

The melon should have a hollow sound when you tap it, Iovine says. A dull sound means it is starting to dry out in the middle or not ripe enough.

Whether you like your melon with or without seeds is a personal matter. Some people swear the seeds enhance the flavor.

With so many market customers who walk or ride bikes, Iovine says he sells more sliced halves or quarters than whole melons. Those should be "nice and tight and full of color," he says, with no cracks.

Yellow-fleshed watermelons make for nice contrast with the red when they're cut up and served together. But the red is definitely sweeter.

Sugar Babies, those exceptionally dark round melons the size of soccer balls, seem made for small families.

And don't worry about that yellow patch of color on the bottom of a traditional melon. That's just a sign that it ripened on the vine.

Watermelon-Ginger Relish

Makes 4 servings

3 cups diced, seeded

watermelon

3 tablespoons sliced

scallions

2 tablespoons finely chopped fresh, flat-leaf parsley

1 tablespoon lemon juice

1 teaspoon sugar

1 tablespoon rice wine

vinegar

2 teaspoons, grated, peeled fresh ginger

1/4 teaspoon salt

1/4 teaspoon dark sesame oil

1. Combine all ingredients in a large bowl.

2. Cover and chill, serve over grilled fish or chicken.

Per serving: 45 calories, 1 gram protein, 11 grams carbohydrates, 8 grams sugar, trace fat, no cholesterol, 148 milligrams sodium, trace dietary fiber.

Watermelon and Prosciutto Salad

Makes 1 serving

1 ounce yellow watermelon, cut in small cubes

1 ounce red watermelon, cut in small cubes

2 ounces fresh mozzarella, sliced 1/4-inch thick

1 ounce balsamic vinaigrette

2 ounces prosciutto, sliced thin

4 pieces cooked, chilled asparagus spears

3 slices tomato, cut 1/8-inch thick

Drizzle of vegetable oil

Salt and pepper to taste

   1. Season vegetables with salt, pepper and vegetable oil. Grill asparagus for three minutes, turning once. Grill tomatoes for 30 seconds on each side.

   2. Place the watermelon on a plate, lay asparagus across the top, the layer tomatoes, mozzarella and prosciutto across the asparagus. Drizzle with olive oil if desired.