Grow Your Own Lettuce: A Step-by-Step Guide
Updated: Sep 30
To grow lettuce (Lactuca sativa) from seed, sow it thinly on or just below the surface (no deeper than 3 mm), keep the soil moist and cool (10 to 18°C), and thin seedlings to 15 to 30 cm apart. Seeds germinate in 7 to 14 days, baby leaves are ready in 3 to 4 weeks and full heads in 6 to 8. In Ireland and the UK you can sow outdoors from March to August for harvests from late spring to autumn.
Lettuce is one of the quickest, easiest crops for beginners and thrives in Ireland’s cool, damp summers. This guide covers choosing varieties, sowing, care and how to keep salad coming all season.
Lettuce Quick Facts
Latin name: Lactuca sativa
Sowing depth: Surface to 3 mm (seeds need light)
Germination temperature: 10 to 18°C (poor above 25°C)
Germination time: 7 to 14 days
Sow outdoors (Ireland/UK): March to August
Harvest: Baby leaves 3 to 4 weeks; heads 6 to 8 weeks
Spacing: 15 cm (loose-leaf) to 30 cm (crisphead)
Position: Sun or light shade; shade helps in hot spells
Soil: Moist, fertile, rich in compost
Step 1: Choose Your Lettuce Type
Loose-leaf: fastest and easiest, perfect for cut-and-come-again picking (Oakleaf, Lollo Rosso, Salad Bowl).
Cos (romaine): upright, crunchy heads (Little Gem, Lobjoit’s).
Butterhead: soft, tender leaves and loose heads (All the Year Round, Buttercrunch).
Crisphead: dense, crunchy heads like Iceberg; slower and fussier.
Winter hardy: varieties such as Winter Density or Arctic King for autumn sowing under cover.
Step 2: Sow the Seeds
Direct sowing outdoors
Prepare fine, moist soil enriched with compost.
Sow thinly in rows 20 to 30 cm apart, barely covering the seed (lettuce needs light to germinate).
Water gently and keep the surface moist until seedlings appear in 7 to 14 days.
Starting indoors or under cover
Sow on the surface of modules or trays of seed compost and mist.
Keep somewhere bright and cool, 10 to 18°C. Lettuce often fails to germinate in a hot room or greenhouse in summer.
Plant out when seedlings have 3 to 4 true leaves, after hardening off for about a week.
Step 3: Thin and Space the Plants
Thin seedlings when they are 2 to 3 cm tall, keeping the strongest. Eat the thinnings as micro salad.
Final spacing: 15 cm for loose-leaf, 20 to 25 cm for cos and butterhead, 30 cm for crisphead.
Step 4: Water, Feed and Protect
Water: keep soil evenly moist. Dry soil makes lettuce bitter and causes bolting (running to seed).
Feed: rich, composted soil is usually enough; mulch between rows to hold moisture.
Slugs: the main pest in Irish gardens. Check at dusk, use beer traps, wool pellets or copper, and encourage frogs, birds and ground beetles.
Heat: in hot spells, give light shade in the afternoon to slow bolting.
Step 5: Harvest
Cut-and-come-again: pick outer leaves and let the centre keep growing, for weeks of harvests from one plant.
Baby leaves: cut whole plants 3 to 4 cm above soil at 3 to 4 weeks; many regrow.
Whole heads: cut at the base when firm, usually 6 to 8 weeks after sowing. Harvest in the morning for the crispest leaves.
Step 6: Keep Salad Coming All Year
Succession sow: sow a short row every 2 to 3 weeks from March to August for a continuous supply.
Autumn and winter: sow hardy varieties in August and September to grow under cloches, fleece, a polytunnel or greenhouse.
Summer: sow in light shade and keep well watered to reduce bolting.
Troubleshooting Lettuce
Seeds don’t germinate: too warm or buried too deep. Sow on the surface and keep them cool.
Bolting: caused by heat, drought or long days. Water well, give shade and sow little and often.
Bitter leaves: usually from dry soil or plants starting to bolt.
Holes in leaves: slugs and snails. Protect young plants in particular.
Grey mould or mildew: improve airflow with wider spacing and water the soil, not the leaves.
Companion Plants for Lettuce
Chives and garlic chives: strong scents that help deter aphids.
Carrots and radishes: fit between lettuce rows without competing.
Marigolds and nasturtiums: attract beneficial insects and draw aphids away.
FAQ: Growing Lettuce
When should I sow lettuce in Ireland?
Sow lettuce outdoors from March to August, or indoors from February for early crops. Sow hardy winter varieties in August and September to grow under cover through autumn and winter.
How deep should lettuce seeds be planted?
Lettuce seeds need light to germinate, so sow them on the surface or no deeper than 3 mm, and press them gently into moist soil.
Why won’t my lettuce seeds germinate?
The most common reasons are heat and depth. Lettuce germinates poorly above about 25°C, so sow in a cool spot in summer, and cover seed only very lightly.
How do I stop lettuce bolting?
Keep the soil evenly moist, give light shade in hot weather, choose bolt-resistant varieties and sow little and often so you always have young plants coming on.
Is there a perennial alternative to lettuce?
Yes. Perennial salad plants such as sorrel, sea beet and perennial kale grow back every year without resowing, giving leaves for salads from early spring through autumn.
Salad Without Resowing: Perennial Leaves to Try
Lettuce is quick and rewarding, but it needs sowing every few weeks. If you want salad leaves that come back year after year, a few perennials are worth adding to your plot:
Sorrel: lemony leaves from early spring, lovely in salads. Grow it from our French sorrel seeds or striking red-veined sorrel seeds.
Sea beet: the wild ancestor of chard and beetroot, with tender, spinach-like leaves. Available as sea beet plants or seeds.
Perennial kale: young leaves are great raw in salads, and plants crop for several years. See our Taunton Deane perennial kale.
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