how to plant, grow & care for lettuce
complete growing guide
If you choose your varieties carefully you can have delicious fresh lettuce leaves of every colour and form available to pick from May right through until October. If you have a polytunnel or greenhouse, winter lettuce can keep the supply going right through the year. As one of the most decorative of vegetables, you can have great fun creating patterns in the kitchen garden, or even in the flower border where their foliage can set off other flowering plants beautifully. The key is to sow little and often, that way you can ensure continuity and avoid the gluts that will otherwise occur during the peak of the season. We sell a range of lettuce seeds and lettuce seedlings, chosen for their taste and productivity.
- Common name Lettuce
- Latin name Lactuca sativa
- Type Hardy annual vegetable
- Height & spread 15-30cm
- TLC rating Easy
- Aspect Partial shade
- Spacing 15-30cm
- Yield 1 lettuce per seed, or use as cut and come again over a month.
- Suitable for pots Yes
- Grow in a greenhouse? Early or late in the season.
how to grow lettuce
where to grow lettuce
Soil type: Plant your lettuces in moist, well-drained soil. Ensure there is plenty of organic matter in the soil as this will also stay moist and provide the high levels of nitrogen that leafy plants need.
Aspect & Position: Choose a spot in partial shade – lettuces will run to seed if they are in too much heat.
when to plant lettuce
You can start sowing lettuce seed under cover in February, ready to plant into their final position in April. Alternatively wait until March and direct sow outside. You can then continue sowing just a few seeds at monthly intervals right through until the autumn, ensuring continuity of supply and no gluts.
If you have ordered our seedlings, plant them out 15-30cm apart as soon as they arrive in well prepared soil in the garden or in a container. Keep well-watered and free of weeds.
There are some particularly hardy varieties of lettuce that have been bred specifically for winter conditions and will survive a mild frost. An August sowing of these varieties in a greenhouse or polytunnel can keep you in tasty leaves from September right through to the spring.
how to plant lettuce
Remember that every lettuce seed you sow has the potential to grow into a whole lettuce, so work out how many lettuces you tend to eat in a month and sow accordingly (allowing for the usual losses from slugs and snails, of course). Sadly, they are one of our most perishable vegetables, and do not preserve well.
Alternatively, you may prefer to grow the cut and come again types where you pick individual leaves as and when you need them. If that is the case, choose the variety carefully to ensure that it is suitable to be harvested in that way.
sowing lettuce seeds
The plants will be happiest in a cool north facing bed, where the soil can retain plenty of moisture. Hot weather inhibits germination and increases the likelihood of bolting. Prepare the soil well with plenty of organic matter and ensure you have a finely raked tilth on the surface. If you are direct sowing in rows outside, make a shallow drill of around 1cm deep. In hot dry weather, water the drill before sowing to decrease temperatures and it helps to sow in the evening.
Spread the seed very thinly around 2cm apart and rake a thin layer of fine soil or compost over the top. The seed should germinate in a couple of weeks and will need protecting against slugs and snails. Once the seedlings get to 2-3cm tall you can thin them out to around 15-30cm, replanting the thinnings into any gaps, or eating them as baby leaves.
You can also sow lettuce seeds in modules, seed trays or lengths of gutter under cover and plant out the seedlings into their final position once they are 2-3cm tall. When transplanting make sure you do it on a cool damp day and water the plants in carefully.
growing lettuce in containers
You can grow lettuce quite successfully in containers, as long as they are sited in partial shade, and have sufficient depth of soil not to overheat. Use a peat free multipurpose compost with some garden soil and homemade compost mixed in if you have some available. Cut and come again lettuce is particularly suitable to containers, as you can keep a pot by the back door and just pick a few leaves as and when you need them.
how to care for lettuce
Salads of all types do need regular watering as they are shallow rooted and lose a lot of moisture from their tender leaves. You can mulch them with compost after watering to retain the moisture and this will improve the texture and fertility of the soil at the same time. It will also help to prevent weeds growing between the lettuce and competing for resources.
As a quick growing vegetable, lettuces are useful to grow as a catch crop between slower growing varieties such as brassicas or even potatoes, making use of the partial shade before the leaves grow up to shade them out completely.
Salad leaves will be ready to pick 6 weeks from sowing, and you can continue to pick a few leaves from the base or each plant for the following 3 months. Hearting lettuce will need around 10 weeks to mature, and then will stand for a month or so, depending on weather conditions.
- February: sow seed under cover.
- March: direct sow outside.
- Continue sowing at monthly intervals.
- Keep rows thinned, watered and weeded.
- Sow winter lettuce under cover.
- Harvest protected salad leaves regularly.
pests, diseases & common issues
Tender young lettuce seedlings can attract greenfly, so stay vigilant and squash any you see before numbers can build up. Encourage beneficial insects like ladybirds and lacewings by growing a range of flowering plants nearby.
lettuce root aphid
Lettuce root aphid is a greenfly that lives just under the soil surface and eats away at the roots, causing the plants to wilt in hot weather. It is much harder to control as you cannot see them unless you dig up the plant, and birds cannot help you by eating them. Ensure you rotate your lettuce crop around the kitchen garden to avoid a build-up in the soil.
slugs and snails
Lettuces are a magnet for slugs and snails, which is why many people resort to starting them off indoors. Even your transplants are fair game, so a judiciously placed slug trap nearby will help, as will nocturnal sorties with sharp secateurs. Surrounding the rows with our seaweed granules will also deter them as well as improve the soil, and once the soil is warm enough it is definitely worth treating your salad bed with nematodes which will gradually build up numbers and attack the slugs.
lettuce grey mould
Lettuce grey mould is a fungal infection that thrives in damp conditions, infecting the base of the leaves with fluffy grey growths that can eventually kill off the whole plant. When watering try to avoid wetting the leaves, and if you are growing indoors, increase the ventilation. It tends to enter through wounds in the plant, so if you find it a problem avoid harvesting individual leaves and pick the whole lettuce instead.
lettuce downy mildew
Downy mildew is similar to grey mould and can cause yellow discoloration in the leaves, which eventually turn papery and brown. The treatment is the same, and some varieties are more resistant than others, so grow a good mix to ensure success.
Yellow mottling and veining can be a sign of virus that is spread by aphids. Remove and destroy affected plants and ensure you use a new area of the garden each year.
why are my lettuce seedlings leggy or floppy?
Lettuce seedlings get leggy if they are short of light as they are reaching up to try to find it. So, ensure they are in the strongest light possible indoors, or move them outside to a brightly lit area, as probably you should be starting to harden them off before planting them outside. If they are also flopping over, this is either because they are in need of water, or actually have too much – either cause has the same effect, the plants wilt due to stress.
why is my lettuce growing so tall?
This could be for the reason explained above, that the plant is starved of light. Whilst lettuce happily germinates on a windowsill, it will soon need more light as it grows into maturity. Move it outside to a balcony or garden as soon as you can.
why is the lettuce in my garden bitter?
Lettuces start to taste bitter as they begin to flower and go to seed. If you spot a central stem beginning to emerge, a flower will not be far behind as the lettuce puts all its energy into setting seed for the next season.
frequently asked questions
does lettuce need full sun?
Whilst lettuce needs some sun to prevent it getting leggy and etiolated, lettuce does not want full sun all day as it will dry out too fast and start to bolt. So partial shade is the best bet – sun for around half the day.
can lettuce be grown indoors?
You can certainly grow baby salad leaves on a sunny windowsill, but you will struggle with a full-grown hearting lettuce. Choose from one of our cut and come again collections and you will be able to pick a range of colours and shapes to brighten up your plate.
can lettuce be grown in a greenhouse?
You can certainly grow early spring lettuce and the overwintering types in a greenhouse. But you might well find it too hot and dry to grow lettuce indoors at the height of summer unless you are prepared to shade the glass.
how long does lettuce take to grow?
You can start picking baby leaves as soon as six weeks after sowing, whilst a hearted lettuce will usually need ten to twelve weeks, depending on the weather conditions.
how can I stop lettuce from bolting?
A lettuce will “bolt” or go to seed if it is stressed by too much heat or drought. So do not plant in full sun - partial shade for some of the day is better as the soil can cool down and retain more moisture. Ensure there is plenty of organic matter in the soil as this will also stay moist and provide the high levels of nitrogen that leafy plants need. However, you cannot entirely halt the process. Lettuces are an annual plant which means they are programmed to germinate and set seed within one season. So only grow enough so that you can eat them faster than they want to bolt!
will deer eat lettuce?
I’m afraid most creatures are partial to a bit of lettuce and deer are no exception. Rabbits are famous for it if you remember your Beatrix Potter, and many birds are very keen on pecking the edges of the tender leaves. The one thing (apart from a physical barrier) that I found worked with marauding pheasants and partridges was growing red lettuce – perhaps they are colour blind, but they certainly don’t seem to spot them, so worth a try with deer as well?
where do lettuce seeds come from?
Lettuces, like most of our annual vegetables produce seed from flowers that they grow at the end of the summer. You can allow this to happen naturally and you will get self-sown lettuces coming up in your garden the following spring (the oak leaf types are particularly good at doing this). However, the traditional route is to obtain your seed from a gardening catalogue such as that produced by yours truly!
how to harvest lettuce so it keeps growing?
This technique is often described as “cut and come again” and is particularly good with the non-hearting varieties of lettuce such as the oak leaf or salad bowl types. The key is to have a system of taking just two or three basal leaves from each lettuce in succession, so that they then have a chance to regrow before you come at them again. It works well if you just need to have a few leaves that you want to eat right away for a garnish or in a sandwich. If you are creating a big bowl of green salad or catering for more people, a hearting lettuce is a better bet as it keeps longer in the fridge, and some lucky person gets to enjoy the crunch of the central leaves.
can lettuce survive frost and grow in winter?
There are some particularly hardy varieties that have been bred specifically for winter conditions. They will survive a mild frost, but a heavy prolonged frost will probably kill them as lettuce has such a high water-content. They can be protected with fleece or cloches, or better still, grow them in a greenhouse or polytunnel. An August sowing of our Asolo salad mix has been providing tasty leaves from September right through to spring, whilst our “Best Winter Mix” can provide hearting varieties for much the same period of time.
is lettuce poisonous to cats?
No, it is not, some cats are reportedly very keen to eat lettuce.
what to grow with lettuce
As a quick growing vegetable, lettuces are useful to grow as a catch crop between slower growing varieties such as brassicas or even potatoes, making use of the partial shade before the leaves grow up to shade them out completely. You can also grow between later flowering bulbs such as alliums in the flower border, as they help to hide the ugly dying foliage, and have attractive foliage in their own right.