Romaine lettuce (Lactuca sativa, var longifolia) rises tight at the bottom and loose at the top. You may choose loose romaine leaves any time during the day, but if you visit the garden early in the morning you are going to receive the very best flavor. Romaine lettuce is sensitive to heat and also much better suited for spring and fall gardens in Mediterranean climates and frost-free coastal places. Once the summer heats up, romaine goes into seed in a hurry. Romaine matures between 55 and 65 days after planting, but you don’t need to wait that long to start choosing and enjoying the leaves.
Pick 2 to three person leaves from the outside of each romaine lettuce plant. Use a pair of kitchen scissors or a knife to cut on person leaves at the base.
Begin harvesting individual leaves within a month of planting seedlings and keep through the growing season.
Pick the outer leaves every one or two weeks from each head while leaving the interior leaves to grow and develop.
Pick the entire romaine head at the end of this growing season by pulling the plant up. Manage it at the base so that you don’t crush or bruise the leaves.
Cut the roots off and discard them.
Wash romaine lettuce immediately before using.