Erratic weather this spring led to a slew of late-arriving crops and put a crimp in farmers' cash flows. It also broke the hearts of watermelons across the South.

"The watermelon industry has been seeing a higher-than-normal incidence of the condition known as Hollow Heart," the National Watermelon Promotion Board explained in a recent note to retailers. "While the internal cracking has no negative impact on the taste, quality or safety of the product, its appearance on cutting may raise questions with customers who are not familiar with the symptom."

Cold snaps, heat waves and too much rain cause melons to develop Hollow Heart, which the board is now bravely trying to pitch as a plus: "Kids who grow up around watermelons know from experience that the cracked pieces are actually sweeter since the sugars are more concentrated along the cracks," its website claims.

Here, seven more things that kids who grow up around watermelons know:

1. A chilled watermelon is refreshing, but there are a number of reasons to keep an uncut watermelon out of the refrigerator: Watermelons shed their valuable antioxidants when they're cooled. And it takes just two days at 32 degrees for a melon to develop an off-flavor and lose its red-pink glow. Whole melons will last for at least a week when stored at room temperature.

2. In addition to antioxidants, watermelons are laden with lycopene, which is associated with fighting heart disease and cancer. Studies show watermelon also is good at reducing muscle soreness, relieving dehydration and enhancing circulation.

3. Seedless watermelons, which were considered a rarity just a decade ago, now account for 85 percent of the watermelons grown in the U.S. Invented 50 years ago, seedless watermelons are sterile hybrids produced by a cross-breeding process. But the melons aren't really seedless: They're mature seed-less, meaning they're free of hard black seeds. It's common to find empty white seed coats in seedless watermelons.

4. Because it's difficult to wash most watermelons in the kitchen sink - the average watermelon is about 20 pounds - food safety experts advise wiping them down with a damp cloth before eating, even if the completely edible rind isn't slated for consumption.

5. Wilt and disease have always been enemies of watermelon. In 1954, USDA Vegetable Lab horticulturist Charles Fredric Andrus licked both problems with the Charleston Gray, an oblong, hard-skinned melon that was easy to ship. The melon was so successful that a USDA official in the 1960s estimated that if the agency collected profits from its sale, it could have funded the lab's work for 50 years. Although no longer the top-selling melon, Charleston Gray can be found in the family trees of most hybrids.

6. When choosing a watermelon, look for a watermelon that's firm, unblemished and heavy for its size. There should be a creamy yellow spot on its underbelly, a vestige of it having sat in a sunny field for the proper amount of time. Experts are divided on the efficacy of thumping, but folks who swear by flicking watermelons with their middle fingers listen for a deep, hollow sound.

7. Mark Twain wrote movingly about Southern watermelons in his 1894 novel, "Pudd'nhead Wilson." In a passage quoted by Charles Reagan Wilson in his watermelon write-up for "The New Encyclopedia of Southern Culture," Twain wrote, "The true Southern watermelon is a boon apart and not to be mentioned with commoner things. It is chief of this world's luxuries, king by the Grace of God over all the fruits of the earth. When one has tasted it, he knows what the angels eat."