Production time can be extended by making a series of small plantings 10 to 15 days apart. Crisphead and Romaine lettuces take much longer to reach maturity than leaf lettuce. Start them from transplants to avoid the hot weather. If transplants are used, they should be started indoors or in coldframes about March 10 in eastern, March 15 in central, and March 20 in western Nebraska. They should be ready for transplanting approximately April 15, April 20, and April 25 respectively.
Iceberg lettuce can also be direct seeded like any other lettuce.
As it grows, harvest the crunchy, immature plants to add to salads and to allow space for the remaining plants to fill in and mature. Keep the soil moist for 10-14 days for good germination. Wide-row planting will use your garden space more efficiently than traditional narrow rows. It is important to thin the plants to allow good air circulation between the plants. Thinning also will help prevent foliar diseases.