🥬 Lettuce

Lettuce is the classic salad crop and one of the easiest to grow, giving fresh, tender leaves for months from a few packets of seed. There are many types: crisp cos and iceberg, soft butterheads, frilly and colourful loose-leaf varieties, and hardy winter types.

Homegrown lettuce is crisper and sweeter than bagged leaves, and cut-and-come-again types give repeat pickings from a single sowing. Lettuce grows well in pots and window boxes as well as in beds, and tolerates light shade in the heat of summer.

Varieties to try

Little Gem (small, sweet, reliable cos)Salad Bowl (loose-leaf, cut and come again)Lollo Rosso (red, frilly leaves)Winter Density (hardy cos for autumn sowing)Tom Thumb (tiny butterhead for pots)

Sow thinly outdoors from March, 5 mm deep, in rows 15–30 cm apart, and thin to the final spacing as seedlings grow. Make a new sowing every two weeks until August to avoid gluts. In hot weather, lettuce seed can fail to germinate above about 25°C, so sow in the cool of the evening and water the drill beforehand.

For early crops, sow in trays or modules indoors from February and plant out under cloches in March. In autumn, sow hardy winter varieties in September and October under cloches or in a cold frame. For baby leaves, sow thickly and cut when 5–10 cm tall.

Top tips

• Sow a short row every two weeks.
• Sow in the evening in summer to avoid heat blocking germination.
• Choose heat-tolerant, bolt-resistant varieties for midsummer.
• Use modules for early and winter sowings.

Lettuce needs even moisture: water regularly, especially in dry spells, because stressed plants turn bitter and bolt (run to seed). In midsummer, give plants some afternoon shade, for example beside taller crops. Mulch to hold moisture and keep roots cool.

Slugs and snails are the main enemies, so use traps, wool pellets or night-time patrols and keep the bed free of hiding places. Aphids, lettuce root aphid and grey mould can also appear. Remove damaged outer leaves, space plants generously for air flow and rotate the crop.

Top tips

• Water consistently to keep leaves sweet and crisp.
• Give afternoon shade in hot weather.
• Set slug traps around young plants.
• Thin to the right spacing early.

Watch out for

Slugs and snailsAphidsLettuce root aphidBolting in hot weatherGrey mould

Pick loose-leaf lettuces by taking the outer leaves from around the plant, leaving the centre to grow on and produce more. Hearting types such as cos and butterhead are ready when the heart feels firm; cut them at the base with a sharp knife, leaving the stump, which will often resprout.

Harvest in the morning when the leaves are full of water and the plants are crisp. Cut the whole row of overgrown plants before they start to bolt, because once a flower stem forms the leaves become bitter. Baby leaves are ready within three to four weeks.

Top tips

• Harvest in the morning for the crispest leaves.
• Take outer leaves first from loose-leaf types.
• Cut before the plants bolt.
• Leave the stump; it often regrows.

Use lettuce in salads, sandwiches and wraps, or lightly cook outer leaves in soups and with peas, as the French do. Little Gem is excellent halved and grilled. Mix a variety of leaf types together for colour and flavour, and dress just before serving so the leaves stay crisp.

Wash, spin dry and keep in the fridge in a bag lined with kitchen paper, where they stay fresh for three to five days. Cut-and-come-again lettuce stays best in the garden, picked as required. Lettuce does not freeze or dry successfully, so sow little and often.

Top tips

• Dress at the last minute to keep leaves crisp.
• Store in a bag lined with kitchen paper.
• Dry thoroughly after washing.
• Try grilled halved Little Gem hearts.