The most local of all food can be from your own yard, where you can grow treats you're unlikely to see even at a farmers' market—and help save rare, precious varieties of fruits and vegetables while you're at it. This Moon & Stars Watermelon was pulled from the Cooking Light garden this summer. The circa 19th-century melon was resurrected from the backyard patch of a Missouri farmer in 1980, thanks to Seed Savers Exchange. It's one of more than 12,000 heirloom fruits and vegetables that Seed Savers has brought back from the brink.

One in five backyard gardeners now raise heirlooms, according to the National Gardening Association. Seed Savers membership is up 60% in the last five years. Baker Creek Heirloom Seeds, a Missouri-based heirloom seed company started in 1998 by 17-year-old Jere Gettle, now mails more than 300,000 spring catalogs. There's even an heirloom trade show, now in its second year.

Moon & Stars sports constellations of yellow dots on its rind, plus, usually, one large "moon" spot. It's sweet, almost meaty inside. And it's just one of many heirloom water-melons: White Wonders. Royal Goldens. Sugar Babies ...

Variety, gardeners know, is the spice of a tastier life.