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.
3. Trim back the entire plant when it reaches 3 to 6 inches high, or approximately every 10 days. Cut back to within 1 to 2 inches of the ground. Most loose-leaf lettuce varieties grow back from a severe trim to produce more leaves.
How to Clean Lettuce: Using a Salad Spinner. If you have a salad spinner, this is its shining moment; add the lettuce to the inner basket that sits inside the bowl and fill it with water. Gently massage the lettuce to encourage the dirt to separate. Pull the basket out of the water and dump the water.