Tim Stark has been growing a wide variety of heirloom tomatoes at his farm in Hamsburg, Pa. since 1995. His farm encompasses 58 acres, 8 of which are devoted to heirlooms. These thin-skinned, mixed large heirlooms feature yellow, red, orange and pink varieties that are all field-grown with slightly different flavor profiles. Eckerton Hill Farms heirlooms will be available through September.