How to Grow Lettuce from Seed: Cool-Season Salad Guide
By Paul Smith, pemdasgarden.com
Lettuce is the perfect first crop from seed: it germinates in cool soil when nothing else will, grows fast enough to eat within weeks, and thrives in beds, containers, and even partly shady corners where sun-lovers struggle. It is a cool-season plant at heart — happiest in the mild weather of spring and fall — which makes it the ideal bookend to summer's heat-loving crops.
Lettuce comes in four loose families: leaf (loose, fast, cut-and-come-again), romaine (upright and crunchy), butterhead (soft and tender), and crisphead/iceberg (dense heads, slowest). The sowing basics below apply to all of them.
What You'll Love About Growing Lettuce
Few crops reward beginners this quickly. Leaf types can be ready for first pickings in under two months, and succession sowing means a continuous supply rather than one overwhelming harvest. Lettuce tolerates part shade — in fact it appreciates it in warm weather — and it is one of the best container crops there is. A window box of cut-and-come-again leaf lettuce is a salad garden in miniature.
Find lettuce varieties in our vegetable seed collection.
How to Sow Lettuce Seeds
Timing
Sow outdoors 2 to 4 weeks before your last spring frost — lettuce is cold-hardy and doesn't mind a light frost once up. Make repeat sowings every 2 to 3 weeks through spring, pause during the hottest stretch (or switch to heat-tolerant, slow-bolting varieties), and sow again in late summer for fall harvests.
Sowing Depth
Lettuce seeds are small and need light to germinate. Sow just 1/8 to 1/4 inch deep — scatter over the surface, press in gently, and cover with only a whisper of fine soil or vermiculite. Some seeds left visible on the surface is fine.
Soil Temperature
Lettuce germinates over a wide range, roughly 40 to 80°F, usually emerging in 7 to 14 days — but heat is the enemy. Above about 80 to 85°F, germination stalls or fails (a phenomenon called thermodormancy). In hot weather, sow in the coolest spot you have, water the furrow first, or chill seeds in the fridge for a few days before sowing. Growth itself is best at 60 to 65°F.
Light
Full sun in spring and fall; part shade — especially afternoon shade — in warm weather, which delays bolting and keeps leaves tender and sweet.
Spacing
Sow thickly, then thin to final spacing once seedlings have a few true leaves: leaf lettuce 4 to 8 inches apart, romaine 8 to 12 inches, butterhead and crisphead 10 to 15 inches. (Thinnings are edible — your first micro-harvest.) For cut-and-come-again beds, many gardeners sow leaf types in wide bands and harvest young.
Soil
Rich, moisture-retentive but well-drained soil grows the sweetest lettuce. Work compost into the bed before sowing; lettuce's shallow roots can't chase nutrients far.
Caring for Lettuce Plants
Watering. Consistent moisture is everything — lettuce has shallow roots and turns bitter and tough when drought-stressed. Water regularly so the soil never fully dries out, ideally in the morning. Mulch with straw to hold moisture and keep leaves clean.
Feeding. Compost-enriched soil is usually sufficient for such a fast crop. If growth is pale and slow, a light dose of balanced liquid fertilizer helps, but heavy feeding isn't needed.
Succession sowing. The pro move: sow a small batch every 2 to 3 weeks instead of everything at once. You get a steady supply of prime leaves instead of a glut followed by a gap.
Beating the heat. When temperatures climb, lettuce bolts — sends up a flower stalk and turns bitter. Delay it with afternoon shade or shade cloth, generous watering, mulch, and slow-bolting varieties bred for summer. Once a plant bolts, it's done; pull it and sow the next round.
Pests. Slugs and snails love lettuce; aphids cluster on stressed plants. Handpicking, beer traps or boards for slugs, and strong water sprays for aphids handle most issues. Row cover keeps many pests off entirely.
Harvesting Lettuce
For cut-and-come-again leaf types, pick outer leaves when they're big enough to eat and let the center keep growing — one planting yields for weeks. Or cut the whole plant about an inch above the base; many varieties regrow a second flush. For head types, harvest the full head when firm and well-formed, cutting at the base in the cool of the morning. Morning-picked lettuce is at its crispest and sweetest.
Common Mistakes to Avoid
- Sowing in hot soil. Above ~80°F, seeds may simply refuse to sprout — wait for cool weather or use heat-tolerant varieties.
- Burying seeds. They need light; deep sowing means no germination.
- Letting soil dry out. Inconsistent water equals bitter, tough leaves.
- Planting everything at once. One big sowing means one big glut — stagger for steady salads.
- Ignoring bolting. Once the flower stalk rises, flavor is gone; harvest before or replant.
Salad, on Repeat
Lettuce is proof that the simplest crops are often the most satisfying: shallow seeds, cool weather, steady water, and regular picking add up to endless fresh salads. Pair your salad bed with the summer's essential herb — read our guide "How to Grow Basil from Seed" next.
Related Growing Guides
Planting times vary by climate and region — adjust sowing dates for your USDA zone and local frost dates.
Free planning tools: put this guide to work with the Seed Starting Calculator and Succession Planting Planner on our Gardening Tools hub.
Frequently Asked Questions
Why won't my lettuce seeds germinate?
Heat is the most common cause. Lettuce germinates best in cool soil (around 60–65°F / 15–18°C) and stalls in hot weather. Sow in early spring, late summer for fall, or chill seeds briefly before a summer sowing.
Can I grow lettuce through summer?
Yes with care: choose heat-tolerant varieties, give afternoon shade, keep soil moist, and harvest young. Or pause and sow again in late summer for fall salads.
How often should I sow lettuce?
Every 2 to 3 weeks from spring through early fall. Succession sowing is the secret to never-ending salads instead of one overwhelming harvest.
Can I harvest lettuce more than once?
Yes — cut outer leaves and leave the center growing point, and most leaf lettuces keep producing for weeks (cut-and-come-again).