To define a number range, you have to create a new number interval: 1  Specify an alphanumeric key with up to 2 characters. 2  Specify the limits of the number interval.  Mark the number range if it is planned for external number assignment.
Inspect the lettuce plants for leaves that are ready to harvest. Most leaves are mature enough once they reach 1 to 3 inches long, but they should still be tender up to 6 inches long. Cut off the outer leaves of the plants with a small pair of garden shears to harvest just a few leaves.
Harvesting and Storing Lettuce. Harvest looseleaf lettuce by 2 methods. The best way is to start picking the outer leaves of each plant when they get to be 2 to 3 inches long. Continue picking this way for 4 to 6 weeks until the plant goes to seed (the flower spike grows up out of the center--also called âbolting.â).