Growing notes
Lettuce does best in cool weather with ideal conditions being nighttime low temperature of 50°F and up to 68°F daytime high temperature. These plants may bolt in response to long days, high light intensity, and heat.
Harvest signs
Iowa State Extension ↗Harvest single leaves as soon as they reach a usable size. Leaf lettuce and spinach are typically harvested when leaves are 4 to 6 inches long.
▶Planting reference— Depth, spacing, pH, light
▶Pests & diseases— cutworms, slugs, flea beetles, aster yellows
Companions & antagonists
Common questions
How much water does lettuce need?
Lettuce is water-sensitive — shallow roots and a steady thirst. Keep soil moisture in roughly the 40–65% range and don't let it dry out fully, or growth stalls and leafy crops turn bitter.
Can I grow lettuce in a raised bed or container?
Yes — lettuce does well in raised beds and is happy in a decent-sized container too, as long as drainage is good.
Does lettuce come back every year?
No — lettuce is an annual. It completes its life in one season, so you replant it each year.