UK crop guide
Lettuce is not one sowing. The RHS splits the year by the harvest you want: outdoor sowings from late March to late July for summer and autumn, an early August sowing for early winter if you can cover the plants, and a September or October sowing of a winter variety for spring.
Loose-leaf types are ready in as little as four to six weeks. Hearting lettuces take about 10 to 14 weeks, and they need more room or they will not form a heart.
For the earliest outdoor crop, sow indoors in early February and plant out in early March under cloches. In a cold region, March sowings are also safer started inside and planted out after you have hardened them off.
Winter varieties such as Winter Density are sown in September or October in a greenhouse, or under cloches or in a cold frame in mild areas, for harvests the following spring.
From late March to late July, sow a short row every couple of weeks. In the south, once the soil feels warm, seed can go straight into a drill about 1cm deep. Water the drill first. Thin in stages until hearting lettuces are about 30cm apart and loose-leaf types about 15cm apart. The thinnings are salad.
An early August sowing, covered with cloches from late September, is the RHS route to early winter leaves. August sowings also need shade from fierce sun while they germinate, or they fail in hot soil. Sow between slower crops such as sweetcorn if you need the space back later.
Containers work. A pot at least 30cm wide and deep, in a sunny place, will take loose-leaf plants at 15cm. In spring and in colder regions, a fleece or cloche helps them establish.
Pick in the morning while the leaves are still full of water. Loose-leaf plants can be cut as soon as the leaves are about 10cm long. Take a few leaves from each plant, or cut the whole top and leave a short stem to reshoot, as long as the weather is not very hot and dry.
Cut a hearted lettuce through the stem, leaving a stump about 2.5cm tall. It often sprouts a smaller second cut. With the right varieties and some cover, the RHS says you can pick from late spring through to winter.
Long days, a dry spell and a check in growth make lettuce throw a flower stem and turn bitter. Sow little and often, water in dry weather, and do not rely on one spring sowing to last all summer. Winter varieties are for the cool months, not for June.
Hearting varieties planted too close stay as a loose rosette. Give them about 30cm. Loose-leaf varieties are the ones to crowd a little, at about 15cm, if you only want leaves.
August sowings are useful, but lettuce germinates poorly in hot, dry soil and in full glare. Gardeners' World says to keep August lettuce out of direct sun. Water the drill before you sow, and use a module sowing in the shade if the bed is baked.
Kit for this crop, based on the method above.
A fine compost for modules and small pots. The RHS recommends peat-free mixes.
For crops started under cover. Deep pots suit peas, beans and sweetcorn.
For early sowings and for covering tender plants if a late frost is forecast.
Useful for warming a row before you sow, and for protecting early carrots and salads.
Variety and sowing date, so succession sowings do not get mixed up.
A fine rose avoids washing small seed out of the drill.
Yes. The RHS suggests an early August outdoor sowing for early winter leaves, with cloches on from late September. Keep that sowing out of harsh sun while it germinates. September and October sowings should be a winter variety, under cover unless you are in a mild spot.
About 15cm for loose-leaf types and 30cm for hearting types. A hearting lettuce that is cramped often never forms a proper head.