80 - 90 days. These non-GMO Great Lakes 118 lettuce seeds grow into large green leaves and a white heart. Great Lakes 118 Lettuce, also known as Head Lettuce, is ready to harvest in 80 to 89 days. The Great Lakes 118 thrives in full sun or partial shade, being heat resistant, and can be grown in zones 3-9. The leaves of the Great Lakes 118 have a mildly sweet flavor. Non-GMO Great Lakes 118 Crisphead Lettuce (Lactuca sativa "great lakes 118"), is also known as Great Lakes or Head Lettuce. An easy to grow, heat resistant type of lettuce, perfect for beginners. Annual in zones 3-9. Excellent on sandwiches, and in salads. Approx 16,000 seeds per ounce.