Lettuce is a semi-hardy vegetable that grows best in cool weather or partial shade during the summer. Leaf lettuce is easy to grow, and is planted 4 per square. Head lettuce takes longer to mature, and needs consistent cool temperatures to grow well. It is planted 1 per square.
Lettuce can be planted directly in the garden 2 weeks before the frost date. To have a continuous harvest, don’t plant all the lettuce at once. Instead plant a square or two (4-8 plants) every 2 weeks.
To harvest lettuce sooner, start seeds indoors 4 weeks before the frost date, or purchase transplants.
Harden off and transplant outside 2 weeks before the frost date.
Some say lettuce can be started even sooner. If you want to try, keep in mind that lettuce can tolerate freezing temperatures, but won’t do well past 25°F.
Plant seeds directly in the garden 8 weeks before the frost date.
If daytime temperatures are still over 80°F, start seeds indoors 8 weeks before the frost date, or purchase transplants (if available).
Harden off and transplant outside 6 weeks before the frost date, or as soon as daytime temperatures are below 80°F.
The plants will mature more slowly in the fall because the days are shorter. If you provide some protection, you can continue harvesting after the first fall frost.
If you live in a mild climate with no fall frost date, you can plant lettuce from seed and grow it all during the winter.
Soil and Fertilizer
Lettuce grows best in a rich soil; amend with lots of compost and fertilizer (chemical or organic) at planting and once during the season.
Fertilizer: 16-16-8 at planting, 21-0-0 four weeks later.
Harvest from the outside in, letting smaller leaves continue to grow.