Many gardeners have heard the term "heirloom tomato" but don't really know what it means. Happily, it's an easy definition: a variety that has been passed down from gardener to gardener. Unlike modern hybrid varieties, heirloom tomatoes come true from seed, making them easy to share.
The main reason to choose heirloom varieties is the flavor. There's no one heirloom-tomato taste; you'll find a wide range of flavors in the heirloom-tomato world. But many heirlooms are prized for having an old-time taste -- they're a far cry from tomatoes at the grocery store, or even from many modern hybrids like 'Better Boy' or 'Early Girl'.