RHS Growing Guides
How to grow lettuce
Our detailed growing guide will help you with each step in successfully growing Lettuce.
Getting Started
Lettuces are easy to grow, and come in many colours, flavours and textures – your salads need never be boring! Choose from large, hearting lettuces to loose-leaf types and salad-leaf mixes for growing in even the smallest spaces.
Lettuces are best sown regularly in small batches to provide continuous harvests and avoid gluts. This is particularly true with hearting lettuces, which should be cut as soon as they mature, before they flower (bolt), so you only need a few ready at the same time. Loose-leaf lettuces and salad-leaf mixes are even more simple and speedy to grow than hearting types and are harvested as a cut-and-come-again crop over several weeks.
Although lettuces are easy to grow, they usually need protection from slugs and snails. Hot, dry weather can trigger premature flowering, which turns the leaves bitter, so keep them well-watered and lightly shaded in summer, and re-sow regularly so you always have replacements on hand.
Home-grown lettuces beat shop-bought versions hands down for freshness, flavour and choice. So why keep forking out for plastic-wrapped lettuces that all too often end up wilting in the fridge? It makes much more sense to grow them yourself, to enjoy whenever you want them, at their tastiest, nutritious best.
Month by Month
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Choosing
Hearting lettuces
With their dense centre, these lettuces generally take up to three months to reach harvesting size and you then cut the whole head. These are best grown in the ground, as they take up more space, but can also work in large containers. There are three main types:
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Butterhead lettuces have an open shape and soft juicy leaves with a mild flavour. They are fairly quick to mature and tolerate poorer growing conditions. Eat them fresh as they don’t store well
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Cos lettuces (also known as romaine lettuces) have an upright, oblong head and the leaves have a crisp mid-rib. They come in various sizes, including compact ‘Little Gem’, which is ideal when space is tight or when you only want small servings
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Crisphead lettuces produce large hearts of curled, crisp leaves with a mild flavour. They are more resistant to bolting (flowering prematurely) and store well in the fridge. This type includes the popular iceberg lettuces
Loose-leaf lettuces and salad-leaf mixes
These produce less dense rosettes of foliage, ideal for picking individual leaves and for growing in small spaces and containers. They can be highly decorative, both in the garden and on the plate, with a range of leaf colours, shapes, textures and flavours. These are quicker to grow than hearting types and you can often pick your first leaves only about a month after sowing, and continue for several weeks on a cut-and-come-again basis.
More inspiration
For easy, reliable and tasty varieties, look for those with an RHS Award of Garden Merit (AGM), which shows they performed well in trials – see our list of AGM fruit and veg (135kB pdf) and our Recommended Varieties below. Also, for more veg-growing inspiration, visit the RHS gardens, which all grow a range of lettuces and salad crops.
What and where to buy
Most gardening retailers sell a wide choice of lettuce seeds – you can buy a single variety or a mix of varieties offering different flavours and leaf colours. Although lettuce seeds are cheap, they don’t generally store well, so it’s best to buy fresh seeds each year, for more reliable germination. Packs of plug plants are also available from most garden centres and online gardening retailers through spring and early summer, although the choice of varieties is more limited.
Recommended Varieties
Preparing the Ground
Choose a growing site with fertile, moisture-retentive soil. A sunny spot is usually best, but if sowing/planting in the middle of summer, some light shade is preferable during the hottest part of the day, as too much heat can cause lettuces to flower prematurely.
Weed the ground thoroughly and remove any large stones, then dig in plenty of garden compost, to help retain moisture. Alternatively, if you're practising no-dig, mulch the ground ahead of sowing or planting directly into the mulch.
Sowing
Lettuce seeds can be sown indoors or outdoors, in containers or in the ground, from spring through to autumn. Lettuce plants, especially loose-leaf varieties, take up very little space, so are handy for filling any small gaps on the veg plot. They can also be sown between slower-growing crops, such as parsnips and sweetcorn, as they will be harvested before the main crop needs the space.
When to sow
This depends on when you want to harvest:
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For summer and autumn harvests: sow outdoors from late March to late July. For an even earlier crop, sow indoors in early February and plant out in early March under cloches
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For early winter harvests: sow outdoors in early August and cover plants with cloches from late September onwards. Alternatively, grow in a greenhouse border or container
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For spring harvests: sow a winter variety such as ‘Winter Density’ in September/October, either in a greenhouse or in mild areas under cloches or in a coldframe
When sowing in summer, bear in mind that high temperatures can prevent some varieties from germinating. So during hot spells, sow in the evening, water with cold water and provide some shade to keep temperatures down.
Sowing indoors
Carefully move seedlings into individual modules/pots once they have a few leaves and are robust enough to handle – see our video guide to pricking out, below. Then plant them outside from spring onwards, once they’re growing strongly (see the Planting section below). During the colder months, they are best kept under cover, planted in a greenhouse border or large container.
Sowing outdoors
Sow lettuce seeds thinly into prepared soil (see above), 1cm (½in) deep, in rows 30cm (1ft) apart. Sow a short row every fortnight to provide non-stop harvests and avoid gluts.
Thin out lettuce seedlings gradually to 15–30cm (6–12in) apart – check the seed packet for exact spacings. Thinning is particularly important with hearting lettuces, as they may not form a firm head if overcrowded. The seedlings you remove can be added to salads.
Protect lettuce seedlings and young plants from slugs and snails. In early spring, you may also need to protect them from birds and cold temperatures by covering with cloches or plastic-free fleece.
Sowing in containers
Planting
Space larger hearting lettuces about 30cm (1ft) apart – if planted too closely, they won’t form good hearts. Plant smaller loose-leaf types about 15cm (6in) apart. In spring and in colder regions, plants will establish more quickly if covered with cloches or plastic-free fleece.
In hot weather, young transplants can quickly wilt, so water regularly and choose a lightly shaded spot, which should also deter bolting. Protect lettuces from slugs and snails, especially in damp weather. Early in the year, birds can be a problem too, as they find young lettuces irresistible. Protect with plastic-free fleece, chicken wire or similar.
Winter harvests
Hardy lettuce varieties provide harvests over winter and into early spring. Plant plug plants in late summer or early autumn in a greenhouse border, or in large containers to keep in a greenhouse or coldframe. In warm locations you could plant outdoors under cloches.
Plant Care
Watering
Water young seedlings and newly transplanted lettuces regularly in warm, dry weather. Aim to keep the soil consistently moist, as a lack of water can cause bolting, which ruins the crop. Plants in containers are particularly vulnerable, as the compost can dry out rapidly, so keep them out of the midday sun and check them regularly – they may need watering daily in summer.
The best time to water is early in the morning, to set the plants up well for the day. Try to avoid watering in the evening, as the dampness can attract slugs and snails overnight, as well as encourage fungal diseases such as grey mould. For more water-wise tips, see our guides below.
Mulching
Apply a thick layer of mulch, such as garden compost, around lettuce plants once they are growing well, to help hold moisture in the soil and stop it drying out in hot weather.
Feeding
Lettuces don’t usually need feeding, but if you grow them in a container, you can apply a general-purpose organic liquid feed fortnightly through the summer.
Weeding
Keep seedlings and young lettuce plants free of weeds, so they don’t have to compete for water or sunlight, which can slow their growth. Dense weeds can also offer hiding places for slugs and snails, and reduce air circulation, which can encourage fungal diseases such as grey mould.
Bolting
Harvesting
Whole lettuces are ready to harvest when a firm heart has formed – cut through the stem leaving a stump about 2.5cm (1in) tall. This should re-sprout leaves to give you at least one, if not two, additional smaller harvests.
Loose-leaf varieties can be harvested as soon as the leaves are big enough to be worth eating, when about 10cm (4in) long. Harvest as a cut-and-come-again crop – either snip a few leaves from each plant along the row, or let plants grow to maturity and snip all the top growth in one go, leaving a short stem that should re-sprout at least one more crop of foliage, as long as the weather isn’t too hot or dry.
Problems
Lettuces are attractive to various garden creatures, including slugs and snails, aphids and cutworms, while birds sometimes peck young seedlings in early spring. In cool, humid summers, grey mould may affect the leaves, and in hot, dry weather lettuces may start flowering (bolting), which turns the leaves bitter. Hot weather can also reduce seed germination, so in summer sow on cooler days or in the evenings, once temperatures drop. For more on these and other issues, see Common problems, below.
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