When to Plant Lettuce: Cool-Season Timing by Zone
Lettuce is the opposite of tomatoes, peppers, and cucumbers: it is a cool-season crop that prefers cool weather and tolerates light frost.
It bolts (goes to seed) and turns bitter in hot weather.
Your planting windows are therefore in early spring and again in late summer/fall, timed to mature before summer heat or before hard frost.
Lettuce is also one of the fastest crops — you can start it from seed directly in the garden, or sow successive rounds every 2 to 3 weeks for a continuous supply.
Why Lettuce Prefers Cool Weather
Lettuce grows best when air temperatures are 60–70°F (15–21°C).
In heat above about 80°F (27°C), it tends to bolt — sending up a flower stalk and turning bitter.
It tolerates light frost and will even survive some freezing, so it can go in the ground before the last frost.
The result: lettuce is planted in the cool months — early spring for a summer crop, and late summer for a fall crop — and in mild climates can be grown nearly year-round.
Early Spring Planting Window
In most zones, sow lettuce seeds outdoors 2 to 4 weeks before your average last frost date, and keep sowing every 2 to 3 weeks through spring for continuous harvest.
Seeds germinate in cool soil (as low as 40°F/4°C, ideally 60–70°F/15–21°C).
For an even earlier start, sow indoors 4 to 6 weeks before the last frost and transplant young plants; or use a cold frame.
In very cold zones, a row cover helps early plantings.
Fall Planting Window
Because lettuce bolts in heat, a fall crop is often better than a second spring crop in warm regions.
Sow lettuce 6 to 8 weeks before your average first fall frost date, so plants mature as the weather cools.
In mild zones (roughly 8 and warmer), you can sow through fall and even winter, harvesting into early spring.
Choose slow-bolting varieties for late plantings.
- Early spring: sow 2–4 weeks before last frost; keep sowing every 2–3 weeks.
- Fall: sow 6–8 weeks before first fall frost for a fall/winter harvest.
- Succession: sow a small round every 2–3 weeks for steady supply.
Zone-by-Zone Planting Windows
The table below shows representative lettuce sowing windows by USDA hardiness zone.
These are averages: coastal areas and mild climates allow longer cool seasons; hot inland valleys narrow them.
Confirm your dates with your county extension office.
- Zones 3–4: sow early April to early June; sow again late July to late August for fall.
- Zone 5: sow late March to late May; sow again early August for fall.
- Zone 6: sow mid-March to late May; sow again mid-August for fall.
- Zone 7: sow early March to mid-May; sow again late August for fall.
- Zone 8: sow mid-February to April; sow again September for fall.
- Zone 9: sow January–February; sow again September–November for fall/winter.
- Zone 10: sow nearly year-round, avoiding the hottest summer weeks.
Planting Lettuce Correctly
Sow lettuce seeds shallowly — about 1/4 inch deep — in fertile, well-drained soil in full sun or light afternoon shade in warm regions.
Keep the soil evenly moist, since lettuce seeds need moisture to germinate. Thin seedlings so plants are 6 to 12 inches apart (more for head lettuce).
For a cut-and-come-again harvest, harvest individual outer leaves instead of the whole head.
Soil and Season Considerations
Lettuce prefers soil around 60–70°F (15–21°C) and dislikes hot, dry conditions. Mulch keeps soil cool and moist.
In summer heat, grow lettuce in partial shade or under shade cloth to delay bolting.
Choose slow-bolting (bolt-resistant) varieties for late spring and fall sowings.
Signs You Planted Too Early or Too Late
Lettuce planted too early in cold, soggy soil may germinate slowly or rot; a cold frame or row cover fixes this.
Planted too late in spring, it bolts and turns bitter in summer heat. Planted too late for fall, it may not mature before hard frost.
The fix: time sowings to the cool windows and use shade or row covers to stretch them.
Related Guides
FAQ
- 1
What month is best to plant lettuce?
Lettuce is a cool-season crop, so the best times are early spring (2–4 weeks before your last frost) and late summer for a fall crop. In mild zones you can sow nearly year-round, avoiding only the hottest weeks.
- 2
Can lettuce tolerate frost?
Yes. Lettuce tolerates light frost and will survive some freezing temperatures. That is why it can be sown before the last spring frost and into fall.
- 3
How cold can soil be for lettuce seeds?
Lettuce seeds will germinate in cool soil as low as about 40°F (4°C), with 60–70°F (15–21°C) ideal. It is one of the few vegetables you can sow well before the last frost.
- 4
Why does my lettuce bolt and taste bitter?
Bolting is triggered by hot weather — usually above about 80°F (27°C) — and long summer days. Plant in the cool windows, choose slow-bolting varieties, and add afternoon shade or shade cloth in summer.
- 5
Can I grow lettuce year-round?
In mild climates (roughly Zone 8 and warmer) and with a cold frame in cooler zones, you can extend lettuce well into winter. In most of the U.S., the two main windows are early spring and late summer/fall.
Sources
Onslow County Center, N.C. Cooperative Extension — Easy Container Vegetables“Plant [lettuce] in spring and fall (Feb/Mar and Aug/Sept). Replant every 2–3 weeks for continuous harvest.”
NC State Extension — Vegetable Gardening Handbook (Ch. 16)“Be sure to adjust the planting dates for a specific location by noting the frost date and counting backward on the calendar the days to maturity of the vegetables.”
NC State Extension — Central North Carolina Planting Calendar for Annual Vegetables, Fruits, and Herbs“Some plants are adapted to growing in the cool months of the year and will tolerate some frost (cool-season vegetables).”
Farmers' Almanac — Seed Starting Chart“4 to 6 weeks before last frost: brassicas (broccoli, cabbage, cauliflower, kale, brussels sprouts), lettuce, herbs (basil, oregano).”