What is an heirloom tomato? Heirlooms are generation old varieties. Each year, the seeds are taken from the most productive, best tasting or looking plants and grown the following season. These plants are open pollinated and usually have fun stories and history that has been passed down through the years. With unique flavors and colors, heirloom tomatoes are truly something special. At Sprouts, we like to encourage you to explore these fun varieties and carry a great selection of heirlooms for you to choose from.