Sow short rows of lettuce every month and you will always have a supply of leaves to eat. Plants from January sowings are growing fast and it can be tempting to leave al rows to form large heads, but you are unlikely to eat them all before they bolt. Start picking a few leaves from each plant while they are small and tender. This means you get plenty of tasty young lettuce over several weeks. When plants are finished the next sowing will be ready to pick.