Overview
What lettuce needs, when it crops, and whether it suits your space.
Lettuce is quick: loose-leaf types give pickings about six weeks after sowing. The trick is little and often. Sow a short row every two weeks, not one long one, because lettuce is at its best for only a short time before heat and long days make it bolt and turn bitter. Keep it moist, and give summer sowings some shade.
Quick facts
- Botanical name
- Lactuca sativa
- Soil pH
- 6.0 – 6.5
- Temperature
- 13 – 21 °C
- Hardiness
- Any zone, as an annual
- Time to harvest
- 42 – 90 days
- Propagation
- Seed
Optimal growth
Growing details
- Germination
- 7 – 10 days
- Spacing
- 20 cm (8 in)
- Sowing depth
- 10 mm (⅜ in)
- Frost sensitivity
- Frost hardy
Growing calendar
- Start indoors: February, March
- Sow outdoors: March, April, May, June, July, August, September, October
- Transplant: March, April, May
- Harvest: April, May, June, July, August, September, October, November
Early February indoors for the earliest crop, planted out under cloches (RHS). Late March to late July for summer and autumn; early August, covered with cloches from late September; winter types in September and October. Three- to four-week-old transplants, hardened off. Loose-leaf from about six weeks after sowing; hearting types at 10 to 12 weeks.
Is this plant right for you?
- Fast crop
- Beginner friendly
- Great in pots
- Cool-season crop
- Sow little and often
- Tolerates part shade
- Bolts in heat
Good to know
It does well in a pot indoors or out, so you do not need a bed for it. It stands frost, so it can go out earlier than tender crops.
Before You Grow
Choose loose-leaf for quick picking or a hearting type, and a fertile, moist spot.
Lettuce seed doesn’t keep well: buy fresh each year for reliable germination.
What you need
Fresh seed
A few varieties, bought each year. See choose your lettuce.
Fertile, moist soil
With plenty of compost dug in. See soil.
A watering can with a fine rose
For frequent light watering. See watering.
Shade cloth or taller crops
For summer sowings. See shade and cover.
Cloches or fleece
For early spring and autumn crops.
Slug protection
Lettuce is a favourite. See pests.
Choose your lettuce
Lettuces are either loose-leaf, picked a few leaves at a time, or hearting, cut as a whole head.
Loose-leaf types are the quickest and most adaptable: first leaves four to six weeks after sowing (RHS), and pickings for weeks. Oak-leaf ‘Salad Bowl’ is slow to bolt (RHS); frilly ‘Lollo Rossa’ adds colour. Ideal for pots.
Butterhead (Bibb, Boston) has soft, buttery, open heads, matures fairly quickly and tolerates poorer conditions, but doesn’t store well. It turns bitter in summer heat (UMD).
Cos or romaine has upright heads with crisp midribs: ‘Little Gem’ is compact; ‘Lobjoits Green Cos’ and ‘Sioux’ are RHS AGM varieties; ‘Winter Density’ is hardy and slow to bolt.
Crisphead (iceberg) makes large, crisp hearts that store well and resist bolting in the UK (RHS), but in hot US summers it is the hardest to grow and needs a long, cool season (Illinois, Clemson).
Colour. Red and purple varieties seem less attractive to slugs (Gardeners’ World).
Lettuce types compared
-
Loose-leaf
- Ready
- 4 to 6 weeks
- Bolting
- Some slow to bolt
- Notes
- ‘Salad Bowl’, ‘Lollo Rossa’
-
Butterhead
- Ready
- About 9 to 10 weeks
- Bolting
- Bolts in heat
- Notes
- Soft, mild; eat fresh
-
Cos (romaine)
- Ready
- About 10 to 12 weeks
- Bolting
- Some resistant
- Notes
- ‘Little Gem’, ‘Lobjoits Green Cos’, ‘Winter Density’
-
Crisphead (iceberg)
- Ready
- About 12 weeks
- Bolting
- Resistant in cool summers
- Notes
- Stores well; hardest in heat
Timings from Gardeners’ World, the RHS and Illinois. For a first sowing or a pot, a loose-leaf mix.
Where lettuce grows best
Lettuce is a cool-season crop. It grows best at average temperatures of about 13 to 21 °C (55 to 70 °F) (Clemson, Illinois), and tastes best when it grows fast and matures before summer heat.
Heat. Above about 24 °C (75 °F), growth slows; long days and heat make lettuce bolt and turn bitter (Utah State, UMD).
Light. Full sun in spring and autumn. It tolerates part shade, four to six hours of direct sun, and summer crops do better with afternoon shade (UMD, RHS).
Cold. Semi-hardy: it takes light frosts, and young plants tolerate 0 °C (32 °F) (Utah State). Protect it from hard frost.
Wind. Shelter seedlings, which dry out fast in wind (Clemson).
- Best growth
- 13 to 21 °C (55 to 70 °F)
- Bolts above
- About 24 °C (75 °F)
- Part shade
- 4 to 6 hours of sun is enough
Soil
Lettuce likes fertile, moisture-retentive soil rich in organic matter.
Preparation. Weed, remove large stones, and dig in plenty of garden compost (RHS). Compost helps stop lettuce bolting in hot, dry weather, especially on light soils (Gardeners’ World).
Fine tilth. Rake to a fine surface so the small seed makes good contact. On heavy clay that crusts, cover seed with potting compost instead of garden soil (Clemson).
pH. 6.0 to 6.5 (Clemson).
Planting
Sow thinly and shallowly, every two weeks, from early spring to late summer.
A short row every fortnight gives steady pickings instead of a glut that bolts.
When to sow lettuce
Sow from spring to autumn, in small batches. The RHS and Gardeners’ World sow a short row every two weeks; Illinois every 10 to 14 days.
In the UK (RHS): outdoors from late March to late July for summer and autumn. Indoors in early February for an early crop under cloches. Early August for early-winter pickings under cloches. A winter variety such as ‘Winter Density’ in September or October, under cover, for spring.
In the US: as soon as the soil can be worked in spring, two to three weeks before the last frost (Utah State), and finish spring sowing a month before hot weather starts (Illinois). Sow again in late summer for autumn.
Hot weather. Germination falls off above about 27 °C (80 °F) (Utah State). Sow in the evening, water with cold water, and shade the seedbed (RHS, Utah State).
- A short row every two weeks.
- Spring and late summer are best.
- In summer, sow in the evening and shade.
How to sow lettuce
Sow thinly and shallowly: lettuce seed is small, and some types need light to germinate.
-
Make a shallow drill
About 1 cm (⅜ in) deep, in rows 30 cm (12 in) apart (RHS, Gardeners’ World).
-
Sow thinly
About 10 seeds per 30 cm (1 ft) (Illinois).
-
Cover lightly
With a thin layer of soil or vermiculite: some lettuces germinate better with light (Gardeners’ World, Illinois).
-
Keep moist
Seedlings appear in 7 to 10 days at 13 to 18 °C (55 to 65 °F) (Utah State).
-
Thin
Gradually to 15 to 30 cm (6 to 12 in) apart for hearting types, about 10 cm (4 in) for loose-leaf. Eat the thinnings.
Raising and planting transplants
Transplants give earlier crops and need no thinning; crisphead does best from them.
-
Sow in modules
Thinly in pots or trays of peat-free seed compost, somewhere warm and bright, then prick out into modules (RHS).
-
Grow on for 3 to 4 weeks
UMD plants out at three to four weeks old.
-
Harden off
Gradually, without letting growth stop (Illinois).
-
Plant out
At the same depth, 20 to 30 cm (8 to 12 in) apart for crisphead, closer for smaller types, and water in.
-
Protect
From slugs straight away, and with cloches or fleece in early spring.
Care
Frequent light watering, shade in summer, cover in autumn, and slug control.
Heat and dry soil make lettuce bolt. Water often and give summer crops afternoon shade.
Care by growth stage
Seedlings
Water: light and often
Keep moist, thin, weed, and protect from slugs. See sowing.
Growing
Feed: once, after a month · Mulch: keeps roots cool
Steady moisture for fast growth. See watering.
Hearting
Water: 2.5 to 5 cm (1 to 2 in) a week
Water evenly so heads fill without bolting or tipburn.
Summer
Shade: afternoon
Shade in the afternoon; resow often. See shade and cover.
Autumn and winter
Protect: cloches from late September
Cover with cloches or fleece against hard frost.
Watering lettuce
Lettuce has shallow roots and needs steady moisture. Dry soil makes it bolt; uneven watering makes leaves tough and bitter and causes tipburn.
How much. Utah State gives 2.5 to 5 cm (1 to 2 in) a week, depending on soil and weather. Clemson moistens the soil to 15 cm (6 in) deep.
How often. Frequent light watering encourages fast growth (UMD, Illinois). Don’t overwater, especially on heavy soil: it causes rot and scorched leaf edges.
When. In the morning, so leaves dry before night (UMD, Clemson). Avoid splashing the leaves in late summer, when downy mildew spreads (Gardeners’ World).
Mulch to hold moisture and keep the soil cool.
Feeding lettuce
Lettuce has a medium to high need for nutrients (UMD), best met by compost dug in before sowing.
Side-dress once, about four weeks after planting or at thinning, with a little nitrogen along the row (Utah State, Clemson). Clemson prefers calcium nitrate, which also helps prevent tipburn.
Shade and cover
Lettuce needs no pruning. What it needs, depending on the season, is shade or cover.
Summer shade. Afternoon shade delays bolting. Grow lettuces in the shade of sweet corn, staked tomatoes or pole beans, between rows of later crops, or under shade cloth (UMD). Heat-tolerant loose-leaf types do best (Illinois).
Spring and autumn cover. Row covers and cloches speed early growth and keep off some pests; fleece gives a few degrees of frost protection, and a cold frame extends autumn and winter crops (UMD, Clemson).
Weeds. Lettuce competes poorly: weed often, and shallowly, so you don’t damage the roots.
Lettuce in containers
Lettuce grows well in pots, troughs and salad tables, especially loose-leaf and compact types such as ‘Little Gem’.
Sowing. Scatter seed thinly over moist, peat-free compost and cover with a fine layer of compost or vermiculite (Gardeners’ World).
Cut and come again. Sow thickly, cut plants just above the compost at 15 to 25 cm (6 to 10 in), and they regrow for another cut if watered and fed (UMD).
Care. Pots dry quickly: water often, and move them into light shade in summer.
Problems
Bolting, bitterness, tipburn and slugs are the usual troubles.
Common lettuce problems
Heat, dry soil and uneven watering cause most of the physical problems below.
A tall stalk from the centre
- Bolting
Long days, heat and age. Harvest at once. Next time sow little and often, shade summer crops and choose slow-bolting varieties.
Bitter leaves
- Heat
- Water stress
Hot weather, dry soil or bolting. Washing and chilling the leaves for a day or two removes much of the bitterness (Illinois, Utah State).
Brown, dead leaf edges
- Tipburn
A calcium problem inside the plant, brought on by uneven watering, heat, wind and fast growth (Clemson). Water evenly; trim the brown edges and eat the rest.
Seed didn’t come up
- Heat
- Old seed
Soil too hot, too dry, old seed, or buried too deep. Buy fresh seed and sow in the evening in summer.
Tough leaves, slow heads
- Uneven watering
Moisture swings (Utah State). Water little and often and mulch.
More problems with lettuce
Common pests
Slugs and snails
A serious pest, especially of seedlings in damp weather. Use grit or copper barriers, or ferric phosphate pellets as a last resort (Gardeners’ World, Clemson).
Aphids
Colonies under leaves, which curl. Wash off with a strong jet of water or use insecticidal soap (Utah State).
Flea beetles
Tiny holes in seedling leaves. Floating row covers keep them off (Utah State).
More problems with lettuce
Common diseases
Downy mildew
Yellow patches with white growth beneath, in wet late summers. Water at the base and space plants for air flow (Gardeners’ World). Some varieties resist it.
Grey mould and rots
Grey mould, bottom rot and drop rot lettuce at soil level in wet or hot seasons (Clemson, Illinois). Good drainage and air flow help; rotate beds.
More problems with lettuce
Harvest & Use
Pick leaves as needed or cut whole heads as they firm, in the cool of the morning.
Harvesting lettuce
Harvest in the early morning, while the leaves are cool and crisp (Gardeners’ World).
Loose-leaf. Start at about six weeks, or once plants are 12 to 15 cm (5 to 6 in) tall. Pick outer leaves as needed, or cut every other plant at ground level to thin the row (UMD, Illinois).
Butterhead is ready when the leaves cup inward to form a loose head. Cos when the leaves overlap into a head 15 to 20 cm (6 to 8 in) tall (UMD). Crisphead when the head is firm. Cut hearting types at soil level with a knife.
Don’t wait. Hearting lettuces are best cut as soon as they mature, before they bolt (RHS). If a stalk starts to rise, harvest straight away.
- In the early morning.
- Leaves as needed; heads as they firm.
- Cut before bolting.
Storing and using lettuce
Lettuce is best eaten as soon as it is picked: leaves go limp quickly in warm weather.
In the fridge. Harvest when dry, remove damaged outer leaves, and keep unwashed in a bag in the salad drawer (UMD). Crisphead keeps about two weeks; leaf and butterhead up to four at best, if the leaves are dry when bagged; Utah State expects one to two weeks. Throw out lettuce that turns slimy or black-spotted (Illinois).
Keep apart from apples, pears and bananas: their ethylene gas browns lettuce (Illinois, Utah State).
Using it. Wash in cold water and shake dry just before use. A glut makes a chilled lettuce soup (Gardeners’ World).
More to Explore
Quick answers, guides that pair well with lettuce, and the sources behind this one.
Frequently asked questions
Why is my lettuce bolting?
Heat, long days, dry soil and age. See common problems.
How do I stop lettuce tasting bitter?
Keep it watered and cool, pick before it bolts, and chill the washed leaves for a day.
How often should I sow lettuce?
A short row every two weeks. See when to sow.
Can lettuce grow in shade?
Partly: four to six hours of sun is enough, and afternoon shade helps in summer.
How far apart should lettuce be?
About 10 cm (4 in) for loose-leaf, 15 to 30 cm (6 to 12 in) for hearting types.
Can I grow lettuce in pots?
Yes, especially loose-leaf and cut-and-come-again mixes. See containers.
Does lettuce regrow after cutting?
Loose-leaf and cut-and-come-again lettuces do, if cut above the base, then watered and fed.
Why didn’t my lettuce seed germinate?
Usually hot soil, dry soil or old seed. Buy fresh seed and sow in the evening in summer.
Related guides
Sources
- How to grow lettuces (opens in a new tab) Royal Horticultural Society
- Growing lettuce in a home garden (opens in a new tab) University of Maryland Extension
- Lettuce in the garden (opens in a new tab) Utah State University Extension
- Lettuce (opens in a new tab) University of Illinois Extension
- Lettuce (opens in a new tab) Clemson Cooperative Extension
- How to grow lettuce (opens in a new tab) BBC Gardeners’ World