Loose-leaf lettuce (Lactuca sativa) is the easiest lettuce type for many beginners. Instead of waiting for one perfect head, you can harvest several outer leaves and let the smaller centre leaves keep growing.
Start small
Choose a loose-leaf variety suited to a cool climate and read its packet. Lettuce likes cool weather, moist soil, and sun, though light afternoon shade can help as days warm. A container works if it has drainage holes and enough room for the packet’s final spacing.
Lettuce seed is tiny. Prepare a smooth surface, sow shallowly at the packet’s depth, and water with a gentle sprinkle so seed does not wash into a heap. Crowded seedlings compete and stay damp, so thin them to the spacing on the packet.
Because lettuce roots are shallow, check the soil often and keep it evenly moist rather than flooded. Hot, dry conditions can make the plant stretch upward to flower—a change called bolting—and the leaves may become bitter.
Pick leaves, not the whole plant
Harvest clean outer leaves when they are large enough to use, leaving the small centre leaves in place. Pick in the cool part of the day and stop using leaves that are slimy, mouldy, badly damaged, or contaminated by animal droppings.
Wash your hands, then rinse the leaves under cool running water. Refrigerate them promptly. Do not use soap or household cleaners on produce.
The lettuce ruler
Choose one leaf without picking it. Once a week, measure from the soil to its tip and trace its shape in your journal. How many new centre leaves appear between measurements? Stop the experiment when that leaf is harvested or begins to age—the plant does not have to cooperate with your plan.