Planting timing · Cool-season
When to plant lettuce
Sow lettuce as a cool-season crop when soil can be worked, matching cited type and geography. Bolting is a separate page. There is no single national planting date.
Growing guidance is general information. Timing, spacing, and care depend on cultivar, weather, soil, and local conditions. Check the sources and adjust the plan for your garden.
Your window
Use your last-spring-frost history — not a national month.
A ZIP calculator is not live on this page. Save the bed to store the window you actually used.
Spring and fall windows are source-specific. Heat-bitter notes live on bolting.
Seed-stalk and bitter-flavor notes live on lettuce bolting.
Cited sowing windows (not a national calendar)
Separate source assertions — not a BioArva average.
- Maryland Extension (Maryland): sow leaf or butterhead types as soon as soil can be worked in the spring, or in late summer; crisphead and cos (romaine) types may be transplanted in early spring and fall. Timing on their sheet — not a national calendar.
- Maryland Extension (Maryland): leaf lettuce on their sheet can be grown from March to December with a break in July and August. Geographic calendar on their sheet — not a national plant date.
- Clemson HGIC 1312 (South Carolina): lettuce is a cool-season crop; their sheet lists temperatures of 55 to 65°F. Temperature range on their sheet — not a BioArva climate zone.
- Clemson HGIC 1312 (South Carolina): their sheet lists soil temperature for seed germination of 60 to 80°F, and says raw lettuce seed will not germinate at a soil temperature above 95°F. Germination range on their sheet — not a BioArva climate zone.
- Maryland Extension (Maryland): their sheet lists 3 to 4 week old transplants. Timing note on their sheet — not a yield promise.
- Illinois Extension (Illinois): lettuce can be planted once soil temperatures are above 40°F but tend to germinate best at 55°F to 65°F. Germination range on their sheet — not a BioArva climate zone.
- Illinois Extension (Illinois): their sheet lists planting lettuce at least a month before summer in the context of heat. Timing on their sheet—not a national calendar.
- Illinois Extension (Illinois): for fall production, lettuce can be planted in late summer to be harvested in the fall. Timing on their sheet — not a national plant date.
- Illinois Extension (Illinois): for an ongoing supply of lettuce greens, do successive plantings 10 to 14 days apart. Succession interval on their sheet — not a BioArva calendar and not a yield promise.
- Wisconsin Horticulture (Wisconsin): plant seeds in the garden as early as 4 to 6 weeks before the average date of last frost. Timing on their sheet — not a national plant date.
- Illinois Extension (Illinois): lettuce is a fairly hardy, cool-weather vegetable that thrives when the average daily temperature is between 60 and 70°F. Temperature range on their sheet — not a BioArva climate zone.
- Illinois Extension (Illinois): leaf, Cos and butterhead lettuce can be planted anytime in the spring when the soil is dry enough to rake the surface. Timing on their sheet — not a national calendar.
- UMN Extension (Minnesota): direct seed as soon as the soil is workable in April. Minnesota calendar on their sheet — not a national plant date.
- UMN Extension (Minnesota): for a fall crop, sow seed about three months before the average first fall frost date. Timing on their sheet — not a national plant date.
Cited seed depth and seedlings (not a BioArva average)
Separate source assertions — not a BioArva average.
- Illinois Extension (Illinois): direct plant seeds ¼ to ½ inch deep with rows 12 to 18 inches apart; they typically overplant at 10 seeds per foot and thin seedlings to 4 inches apart. Spacing on their sheet — not a BioArva average.
- Clemson HGIC 1312 (South Carolina): lettuce seedlings should be protected from the wind because the young plants are tender. Seedling note on their sheet — not a product SKU.
- Wisconsin Horticulture (Wisconsin): lettuce is a cool-weather crop that does best in spring and fall, but there are cultivars that are more heat tolerant – often labeled as “summer lettuce.” Season note on their sheet — not a cultivar ranking or product.
- Wisconsin Horticulture (Wisconsin): most cultivars do best in full sun but many do well in light shade during the summer. Light note on their sheet — not a site ranking.
- Illinois Extension (Illinois): watering is essential for seed germination and establishment of seedlings. Water note on their sheet — not a BioArva irrigation schedule.
- UMN Extension (Minnesota): start seeds indoors in early April for transplanting in late April and early May. Minnesota calendar on their sheet — not a national plant date.
- Clemson HGIC 1312 (South Carolina): lettuce is a cool-season crop that prefers temperatures of 55 to 65°F for optimum growth. Temperature range on their sheet — not a BioArva climate zone.
- Maryland Extension (Maryland): sow leaf or butterhead types as soon as soil can be worked in the spring, or in late summer. Timing on their sheet — not a national calendar.
What to record in the Field Book
Save the bed with the crop and the date. You may add a photo and notes. Compare entries you have recorded with each other — not with a diagnosis from this page. If you want an identification, bring the record to local Extension.
Save this bed. See it coming next year.
Your checks stay in the Field Book so next season is not a guess.
How we know — methodology. Ranges and assertions are cited per source, not blended.