How to Grow Lettuce from Seed

Crisp, fresh salad greens are one of the fastest, most satisfying rewards in the vegetable garden, and once you learn how to grow lettuce from seed you'll never look at a bagged clamshell the same way again. Lettuce is quick, forgiving, and perfect for small spaces, raised beds, and containers. The one thing it truly cares about is temperature — it's a cool-season crop that loves mild weather and sulks in heat. Get the timing right and you can harvest tender leaves within weeks. Here's everything you need to know.

Why Grow Lettuce from Seed?

Lettuce is one of the best crops for beginners because it germinates fast, matures quickly, and lets you harvest a little at a time. Starting from seed also unlocks the huge range of varieties you'll never find as transplants — buttery Bibb, crunchy romaine, ruffled oakleaf, and heat-tolerant summer types. A single packet can feed you for months if you sow in small, staggered batches. Explore the options in our vegetable seeds and pick a mix of colors and textures for your salad bowl.

Understanding Lettuce and Temperature

Temperature is the key to lettuce success. Seeds germinate best when the soil is around 65°F, and they'll sprout in just a few days in that sweet spot. The catch is heat: lettuce seed struggles to germinate once soil climbs above about 80°F, a heat-triggered dormancy that frustrates many summer gardeners. That's why lettuce is a spring and fall favorite in most regions. Plan your main sowings for the cool shoulders of the season, and use shade and timing to stretch it through summer.

How to Grow Lettuce from Seed: Sowing Basics

When to sow

Direct-sow lettuce outdoors as soon as the soil can be worked in early spring, then again in late summer for a fall crop. You can also start seeds indoors 3 to 4 weeks before transplanting to get a jump on the season. In mild-winter areas, lettuce grows happily right through fall and winter.

How to sow

Sow seeds shallowly — no more than a quarter-inch deep. Many lettuce varieties germinate best when sown close to the surface, where some light can reach them, so barely cover the seed with fine soil or vermiculite and keep the surface consistently moist until sprouts appear. Because the seeds and seedlings are small and delicate, a fine, crumbly seedbed makes a big difference. If you're starting indoors, our seed starting supplies make it easy to raise sturdy transplants.

Spacing and thinning

Give leaf lettuce about 6 to 8 inches between plants and head-forming types around 12 inches, with rows roughly 10 to 16 inches apart. Sow a little extra and thin to the strongest seedlings — and don't toss the thinnings, which make a tender baby-greens snack. Crowded lettuce stays small and is more prone to disease, so give each plant room to breathe.

Watering, Feeding, and Care

Lettuce has shallow roots and high water needs, so consistent moisture is essential — let it dry out and leaves turn bitter and tough. Water evenly and often, especially in warm weather, and mulch lightly to keep the soil cool and damp. Because you're growing lettuce for lush leaves, it appreciates nitrogen-rich, fertile soil. Work compost into the bed before planting and side-dress with a balanced or nitrogen-forward feed as plants grow. Our soil and fertilizer selection has organic options well suited to leafy greens.

Succession Planting for a Continuous Harvest

The secret to never running out of salad is succession sowing: plant a short row every 2 to 3 weeks rather than all at once. Because lettuce matures fast and doesn't hold long in the garden before bolting, small, frequent sowings keep tender leaves coming for months instead of dumping one giant harvest at the same time. Mix quick leaf types with slower head types so your harvest window naturally spreads out.

Beating the Heat: How to Stop Lettuce From Bolting

Bolting is when lettuce sends up a flower stalk and turns bitter, and it's almost always triggered by long, hot days — temperatures in the 80–90°F range. Once a plant bolts, the leaves lose their sweetness for good. To push your season further into summer, try these tactics: choose heat-tolerant or “slow-bolt” varieties, provide afternoon shade or a light shade cloth during the hottest hours, keep soil consistently moist, and harvest young before heat sets in. Planting where taller crops cast some afternoon shade also helps.

Days to Maturity and Harvesting

How soon you harvest depends on the type. Loose-leaf lettuce is ready in as little as 40 to 50 days, while head and romaine types take roughly 65 to 80 days or more. You don't have to wait for a full head, though — the “cut-and-come-again” method lets you snip outer leaves an inch above the crown and the plant keeps producing new growth for weeks. Harvest in the cool of the morning when leaves are crisp and full of moisture, and pick regularly to encourage tender new leaves.

Common Problems

Aphids and slugs are the most frequent pests — rinse aphids off with water and manage slugs with traps or barriers. Bitter leaves usually mean heat stress or dry soil, so shade and water are the fix. Seeds that won't sprout in summer are almost always a sign the soil is too warm; wait for cooler conditions or start seeds somewhere cool and transplant. Good airflow and even moisture prevent most fungal issues.

Start Your Salad Garden

Growing lettuce from seed is one of the quickest wins in gardening: sow shallow, keep it cool and moist, stagger your plantings, and harvest young. Whether you have a big bed or a single container on a balcony, fresh-cut greens are within reach. Ready to fill your salad bowl? Browse our vegetable seed collection and sow your first row this week.

Choose a lettuce type for your harvest

Sources and further reading

• University of Minnesota Extension: Planting the vegetable garden