Lettuce is a cool-season crop, and seedlings can tolerate a light frost. Lettuce grows quickly, so stagger the plantings. It is recommended to sow the lettuce seeds directly into the garden as soon as the soil can be worked. Sow every 3 weeks for a continuous supply of fresh lettuce.
For direct seeding, seeds germinate at low soil temperatures (40°F), but poorly above 75°F. Sow seeds 2-3″ apart, rows 12–18″ apart. Cover seed lightly, about 1/8″, and firm soil gently. Thin iceberg and romaine lettuce to one plant every 10–12″, other types 8–10″ for full size heads or 6″ for mini heads. Dry soil must be watered to ensure coolness and moisture, and for uniform germination.
Water lettuce once to twice per week or every 4 days whenever rainfall is inadequate. Lettuce can be picked whenever real leaves form. Pick when the leaves are younger rather than waiting so the taste doesn’t become bitter. For heads of lettuce, cut the plant at the soil line to harvest it. For leaf lettuces, you can harvest the entire plant or only the outer leaves as needed. Harvest in the morning. Store in cool, dark and high humidity location for up to 2-3 weeks.
Bonus Tip: Plant lettuce near taller plants, like tomatoes, so the leaves are in the shade during the hot parts of the day.
