1000+ Iceberg Lettuce Seeds Crisphead Romaine Lettuce Bulk Lettuce seeds USA These NON-GMO Iceberg seeds grow into green heads of lettuce that are ready to harvest in 70 to 79 days. It can be grown in zones 4-9.The Iceberg lettuce is one of the most popular varieties of crisphead lettuce, Its popularity is due to its crisp, juicy texture. The leaves of the Iceberg have a mildly sweet flavor . It has a neutral taste and refreshing crunch, making it a favorite among children. Popular for sandwiches, burgers, and salads. Sow and Grow Start by sowing the NON-GMO seeds 1/2 inch in soil, twelve inches apart, in rows eighteen inches apart. Make sure to allow enough space between seeds for the lettuce to grow, as overcrowding can cause the lettuce to have a bitter taste. Firm the soil lightly. While growing, keep the soil well watered.They prefer cooler weather, but need sunlight to grow properly. If they heat up too fast, or too early, iceberg lettuce could prematurely bolt, or go to seed. Harvest Harvest 70 to 79 days after planting.They are best when harvested just before this point, when the inner leaves are firm. Heat can also cause splitting or rotting, so start lettuce in the early spring so it can be harvested before the high heat of summer.