Lettuce

BeginnerRepeatedly through the seasonPlanted as seed

Lactuca sativa

The quickest crop in the garden, and the one most worth sowing a short row of every couple of weeks. Lettuce wants cool weather and steady moisture; heat and dry soil turn it bitter and send it running to seed.

Light

Full sun (6+ hours)

Full sun in spring and autumn. Once summer heat arrives lettuce does better with shade through the afternoon.

Water

Moderate

Keep the soil evenly damp and never let it dry out; lettuce roots sit in the top few centimetres and a dry spell turns the leaves bitter.

Soil & substrate

Rich and moist

Loose soil with plenty of compost in it. Lettuce is shallow-rooted so the top of the bed is what matters.

Feeding

Moderate feeder

Compost dug in before sowing, then one light feed of nitrogen about four weeks in.

Training

None needed

Nothing to tie up or prune. Two habits do matter: thin the seedlings early, and cut leaf types back to a stub instead of picking leaves off.

Harvest signs

Start cutting as soon as the leaves are big enough to want. Lettuce has no ripeness to wait for, and picking early beats picking late every time.

Life of the plant

Timing shifts with your frost dates — never fixed calendar days

1Germination2–10 days after sowing

Seeds come up fast in cool soil, and they need light to do it, so barely cover them.

2Seedling1–4 weeks after sowing

Thin to final spacing once there are three or four true leaves, and eat the thinnings.

3Vegetative20–45 days after transplanting

The plant fills out fast. Keep the soil evenly damp and watch for slugs.

4Maturation1–3 weeks after the previous stage

Heads firm up. Take them as soon as they feel solid rather than waiting for size.

5Cut and come againfrom the previous stage to 60 days after

Cut leaf types to a stub 25 mm above the soil and they regrow for a second and third picking.

6Floweringfrom the previous stage to 2 weeks after

A stem rises from the centre, the leaves turn bitter and the plant is finished for eating.

Varieties

Looseleaf

Open plants that never form a head, cut repeatedly for leaves rather than taken whole. The fastest to crop and the most heat-tolerant of the four.

Butterhead

Soft loose heads with tender buttery leaves. Quick, tolerant of cool weather and easy in small spaces, but bruises easily and does not keep as long.

Romaine or cos

Upright heads 200 to 250 mm tall with thick crisp ribs. The most heat-tolerant of the heading types and the most bolt-resistant, and it holds in the fridge better than the soft types.

Crisphead or iceberg

Dense round heads. The hardest type to grow well in a garden: it needs a long cool run to maturity and is the first to suffer tipburn and to bolt in heat.

What to watch for

What each one looks like, so you know it when you see it

Slugs and snailsPestHigh susceptibility

Stages affected: Germination · Seedling · Vegetative · Harvest window

Soft-bodied molluscs that feed at night and in wet weather, rasping holes in leaves. Seedlings and low soft foliage are the most at risk, and a single night can take out a row of young plants.

Visual signs: Ragged holes with smooth edges chewed through the middle of leaves rather than at the margins · Silvery dried slime trails on leaves soil and pots, which is the deciding feature · Damage appears overnight and stops in dry sunny spells · Seedlings grazed off at soil level · Slugs or snails found under boards pots and mulch during the day
Damage pattern: Worst after rain irrigation and in humid shaded beds · Feeds at night; plants look untouched by day · Concentrated on low soft leaves near the soil

AphidsPestHigh susceptibility

Stages affected: Vegetative · Maturation · Harvest window

Small soft-bodied sap-sucking insects that cluster on the softest new growth. They reproduce extremely fast in warm weather and are the main insect vector of plant viruses in the garden.

Visual signs: Clusters of small pear-shaped insects on shoot tips buds and leaf undersides · A pair of short tubes (cornicles) projecting back from the rear end, which is the deciding feature · Green yellow brown red or black depending on species, wingless or winged · Curled twisted or yellowing new leaves and stunted shoots · Sticky honeydew on the leaves below, often turning black with sooty mould · White cast skins left on leaves and easily mistaken for live insects · Ants running up and down the stems
Damage pattern: Concentrated on the newest softest growth and worst on heavily fed plants · Honeydew and sooty mould appear below the colony rather than at it · Virus symptoms such as mottling yellowing and distorted growth may follow long after the aphids have gone

Lettuce downy mildewWater mould (oomycete)High susceptibility

Stages affected: Vegetative · Maturation · Harvest window

A water mould and the commonest leaf disease of lettuce. It works up the plant from the oldest leaves in cool damp weather, and because the damage is on the part you eat it costs the crop rather than slowing it. There are many races of the pathogen so resistance in a variety is partial and specific.

Visual signs: Pale yellow patches on the upper leaf surface with angular edges that stop at the veins · White crusty growth on the underside of those patches in damp weather and sometimes on the top as well · Patches turn tan or brown and go papery as the tissue dies · Lowest oldest leaves nearest the soil are affected first · On red varieties the first spots look grey and water-soaked rather than yellow
Damage pattern: Works steadily upward from the bottom of the plant so the outer leaves go first · Angular vein-limited blocks rather than round spots or a general yellowing · Soft rots often follow into the dead tissue and finish the head off · Worst in the cool damp weather of autumn and in crowded beds that stay wet after dew

CutwormsPestMedium susceptibility

Stages affected: Seedling · Vegetative · At planting

The caterpillars of several drab night-flying moths. They live at the soil surface and chew through the stems of young plants at ground level, so you almost always find the damage before you find the caterpillar.

Visual signs: Smooth dull caterpillar up to 40 mm long in grey brown or near black often with faint stripes · Curls tightly into a C shape the moment it is touched or uncovered · Found 25 to 50 mm down in loose soil within a hand's width of the damaged plant · Nothing visible on the plants by day because they feed after dark
Damage pattern: A young plant cut clean through at soil level and left lying beside its own stump · Whole seedlings gone overnight with the root still in the ground · Ragged holes chewed in the leaves that rest on the soil · Damage running along a stretch of row rather than scattered across the bed

TipburnPhysiological disorderMedium susceptibility

Stages affected: Maturation · Harvest window

Not an infection. Brown dead edges appear on the young leaves at the heart of the plant because calcium failed to reach the fastest-growing tissue in time. It follows rapid growth in warm bright weather, and the damage is already done by the time you can see it.

Visual signs: Brown to black dead margins on the young inner leaves while the outer leaves look healthy · Damaged edges dry and papery with a sharp boundary against green tissue · Often only found when a head is cut open · Slimy soft rot sometimes follows into the dead margins and smells sour
Damage pattern: Confined to the youngest leaves at the centre of the plant which is what separates it from every other leaf problem · Appears across a whole bed at once a few days after a hot bright spell rather than spreading plant to plant · Worst on fast-growing crisphead and romaine close to maturity · Never spreads to neighbouring plants and never reappears in the regrowth after a cut

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Lettuce

BeginnerRepeatedly through the seasonPlanted as seed

Lactuca sativa

Light

Full sun (6+ hours)

Full sun in spring and autumn. Once summer heat arrives lettuce does better with shade through the afternoon.

Water

Moderate

Keep the soil evenly damp and never let it dry out; lettuce roots sit in the top few centimetres and a dry spell turns the leaves bitter.

Soil & substrate

Rich and moist

Loose soil with plenty of compost in it. Lettuce is shallow-rooted so the top of the bed is what matters.

Feeding

Moderate feeder

Compost dug in before sowing, then one light feed of nitrogen about four weeks in.

Training

None needed

Nothing to tie up or prune. Two habits do matter: thin the seedlings early, and cut leaf types back to a stub instead of picking leaves off.

Harvest signs

Start cutting as soon as the leaves are big enough to want. Lettuce has no ripeness to wait for, and picking early beats picking late every time.

Life of the plant

Timing shifts with your frost dates — never fixed calendar days

1Germination2–10 days after sowing

Seeds come up fast in cool soil, and they need light to do it, so barely cover them.

2Seedling1–4 weeks after sowing

Thin to final spacing once there are three or four true leaves, and eat the thinnings.

3Vegetative20–45 days after transplanting

The plant fills out fast. Keep the soil evenly damp and watch for slugs.

4Maturation1–3 weeks after the previous stage

Heads firm up. Take them as soon as they feel solid rather than waiting for size.

5Cut and come againfrom the previous stage to 60 days after

Cut leaf types to a stub 25 mm above the soil and they regrow for a second and third picking.

6Floweringfrom the previous stage to 2 weeks after

A stem rises from the centre, the leaves turn bitter and the plant is finished for eating.

Varieties

Looseleaf

Open plants that never form a head, cut repeatedly for leaves rather than taken whole. The fastest to crop and the most heat-tolerant of the four.

Butterhead

Soft loose heads with tender buttery leaves. Quick, tolerant of cool weather and easy in small spaces, but bruises easily and does not keep as long.

Romaine or cos

Upright heads 200 to 250 mm tall with thick crisp ribs. The most heat-tolerant of the heading types and the most bolt-resistant, and it holds in the fridge better than the soft types.

Crisphead or iceberg

Dense round heads. The hardest type to grow well in a garden: it needs a long cool run to maturity and is the first to suffer tipburn and to bolt in heat.

What to watch for

What each one looks like, so you know it when you see it

Slugs and snailsPestHigh susceptibility

Stages affected: Germination · Seedling · Vegetative · Harvest window

Soft-bodied molluscs that feed at night and in wet weather, rasping holes in leaves. Seedlings and low soft foliage are the most at risk, and a single night can take out a row of young plants.

Visual signs: Ragged holes with smooth edges chewed through the middle of leaves rather than at the margins · Silvery dried slime trails on leaves soil and pots, which is the deciding feature · Damage appears overnight and stops in dry sunny spells · Seedlings grazed off at soil level · Slugs or snails found under boards pots and mulch during the day
Damage pattern: Worst after rain irrigation and in humid shaded beds · Feeds at night; plants look untouched by day · Concentrated on low soft leaves near the soil

AphidsPestHigh susceptibility

Stages affected: Vegetative · Maturation · Harvest window

Small soft-bodied sap-sucking insects that cluster on the softest new growth. They reproduce extremely fast in warm weather and are the main insect vector of plant viruses in the garden.

Visual signs: Clusters of small pear-shaped insects on shoot tips buds and leaf undersides · A pair of short tubes (cornicles) projecting back from the rear end, which is the deciding feature · Green yellow brown red or black depending on species, wingless or winged · Curled twisted or yellowing new leaves and stunted shoots · Sticky honeydew on the leaves below, often turning black with sooty mould · White cast skins left on leaves and easily mistaken for live insects · Ants running up and down the stems
Damage pattern: Concentrated on the newest softest growth and worst on heavily fed plants · Honeydew and sooty mould appear below the colony rather than at it · Virus symptoms such as mottling yellowing and distorted growth may follow long after the aphids have gone

Lettuce downy mildewWater mould (oomycete)High susceptibility

Stages affected: Vegetative · Maturation · Harvest window

Visual signs: Pale yellow patches on the upper leaf surface with angular edges that stop at the veins · White crusty growth on the underside of those patches in damp weather and sometimes on the top as well · Patches turn tan or brown and go papery as the tissue dies · Lowest oldest leaves nearest the soil are affected first · On red varieties the first spots look grey and water-soaked rather than yellow
Damage pattern: Works steadily upward from the bottom of the plant so the outer leaves go first · Angular vein-limited blocks rather than round spots or a general yellowing · Soft rots often follow into the dead tissue and finish the head off · Worst in the cool damp weather of autumn and in crowded beds that stay wet after dew

CutwormsPestMedium susceptibility

Stages affected: Seedling · Vegetative · At planting

Visual signs: Smooth dull caterpillar up to 40 mm long in grey brown or near black often with faint stripes · Curls tightly into a C shape the moment it is touched or uncovered · Found 25 to 50 mm down in loose soil within a hand's width of the damaged plant · Nothing visible on the plants by day because they feed after dark
Damage pattern: A young plant cut clean through at soil level and left lying beside its own stump · Whole seedlings gone overnight with the root still in the ground · Ragged holes chewed in the leaves that rest on the soil · Damage running along a stretch of row rather than scattered across the bed

TipburnPhysiological disorderMedium susceptibility

Stages affected: Maturation · Harvest window

Visual signs: Brown to black dead margins on the young inner leaves while the outer leaves look healthy · Damaged edges dry and papery with a sharp boundary against green tissue · Often only found when a head is cut open · Slimy soft rot sometimes follows into the dead margins and smells sour
Damage pattern: Confined to the youngest leaves at the centre of the plant which is what separates it from every other leaf problem · Appears across a whole bed at once a few days after a hot bright spell rather than spreading plant to plant · Worst on fast-growing crisphead and romaine close to maturity · Never spreads to neighbouring plants and never reappears in the regrowth after a cut

Grow it with us

A free account turns this page into a plan for your garden: these stages dated against your own frost, each task as it comes due, what to do about each pest, and the full depth behind every section.

Create a free account Open it in your toolkit