Lettuce

Sun

Full sun in cool weather; light afternoon shade in warm weather.

Water

Keep the root zone evenly moist but not waterlogged. Shallow roots dry out quickly, especially in containers.

Soil

Fertile, moisture-retentive, well-drained soil, ideally pH 6.0-7.0.

Height

0.5-1 ft (0.15-0.3 m) in leaf; flowering stems may reach 3-4 ft (0.9-1.2 m).

Spread

0.5-1 ft (0.15-0.3 m)

Foliage

Soft green, red, bronze or mottled leaves, smooth, crinkled or deeply lobed depending on variety; forms loose rosettes or compact heads.

Growth

Fast; many leaf varieties provide a first picking in 4-6 weeks, while heads take longer.

Care needed

Medium

• Water at soil level whenever the surface starts to dry; do not let seedlings or developing heads wilt.
• Work compost into the bed before planting. In containers, use a balanced liquid feed at the label rate if growth becomes pale or slow.
• Thin or transplant to 6-12 in (15-30 cm) apart, according to the variety's mature size.
• Apply a thin layer of clean mulch once seedlings are established, keeping it away from their crowns.
• Sow small batches every 2-3 weeks during suitable cool weather rather than planting the whole crop at once.
• Use light shade during warm spells and protect young plants from hard frost with fleece or a cloche.

Pruning. No routine pruning is needed. Pick outer leaves without damaging the central growing point, or cut whole heads at soil level; remove plants when they bolt unless you want seed.

Late winter

In mild districts, sow under cover in bright, cool conditions; delay in very cold climates until spring.

Spring

Sow outdoors once soil is workable, covering seed very lightly. Harden off indoor-raised plants before transplanting.

Late spring

Thin seedlings, mulch established plants and begin picking leaves when they are large enough to use.

Summer

Keep soil moist and provide afternoon shade. In hot districts, pause sowing until conditions cool.

Late summer

Sow an autumn crop as temperatures fall; start seed in a cool place if outdoor soil is too warm for germination.

Autumn

Harvest regularly and protect remaining plants from frost. In frost-free districts, continue sowing through the cooler months.

Winter

Clear spent crops in cold districts; harvest protected or outdoor crops where winter temperatures permit.

• Edge vegetable beds with repeated rows of compact leaf lettuces for a tidy, harvestable border.
• Alternate red and green varieties in potagers or geometric beds to create contrasting bands of foliage.
• Grow in wide containers near the kitchen, where leaves are easy to pick and moisture is easy to monitor.
• Use as a short-lived crop between young brassicas or other widely spaced vegetables, harvesting before their canopies close.

Garden styles it suits: Potager (kitchen garden), Edible landscape, Cottage garden, Homestead, Small-space and Family-friendly.

Plant it with: Radishes, Carrots, Spring onions, Chives, Calendula and Kale.

Wildlife: Leaves attract slugs, snails, rabbits and deer. Plants left to flower can provide food for small insects, and birds may take ripe seed.

• Slugs and snails chew seedlings and leaves: inspect after dark, remove hiding places and use labelled iron-phosphate bait where necessary.
• Aphids cluster in leaf folds: inspect frequently, wash off small colonies and remove badly infested leaves.
• Downy mildew causes yellow patches above and pale fuzzy growth beneath leaves: improve spacing, water at soil level and remove infected plants; choose resistant varieties where available.
• Bolting produces a tall flower stalk and bitter leaves, especially in heat or long days: grow in cooler seasons, maintain moisture, provide afternoon shade and replace bolted plants.

Cultivated lettuce is not known to be toxic to people, cats, dogs or horses. Its leaves are edible; large amounts or sudden dietary changes can cause digestive upset in animals.

• Prickly lettuce (Lactuca serriola)

  This wild relative usually has stiff prickles along the underside of the leaf midrib and narrow, often deeply lobed leaves held more upright than most garden lettuce.

• Chicory (Cichorium intybus)

  Leafy forms, including radicchio, can resemble lettuce, but flowering chicory usually has blue flowers rather than lettuce's small yellow flower heads.

• Endive (Cichorium endivia)

  Curly endive has finely divided, often tougher leaves, while broad-leaved escarole can closely resemble lettuce; blue flowers distinguish flowering plants from yellow-flowered lettuce.

Lactuca comes from the Latin lac, meaning milk, referring to the milky sap, while sativa means cultivated.

Propagation. Grow from seed, sown very shallowly in a fine seedbed or modules. Germination is most reliable in cool conditions, roughly 50-68°F (10-20°C), and can be inhibited by hot soil. Saved seed may not come true from hybrid varieties.

Accepted botanical name

Lactuca sativa

In the US and Canada

Introduced in the lower 48 states, Pacific Basin, Puerto Rico and US Virgin Islands.

Native range

Iraq.

Measured

Average height 42 cm.

Sources: GBIF (CC BY 4.0), USDA PLANTS and Trefle (CC BY 4.0). The care and design notes are LandscapeGPT's own.