45 to 55 Days to maturity. Lactuca sativa. Red Tango Leaf Lettuce Seeds. Annual, Heirloom, Open Pollinated, Non-GMO. Red Tango lettuce leaves are red, frilly, serrated, and curled. The lettuce heads are tight and erect. This variety has a somewhat stronger flavor than the related Green Tango lettuce. Approximately 25,000 seeds / oz.