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.
To sow lettuce directly in the garden, simply plant the seeds about 1/4 inch deep, tamp them down, and water. It's that simple! Space the sowings according to packet directions that are based on the size of the mature lettuce. For example, a crisphead may require a square foot of garden space.