Lettuce is a leafy salad that doesn’t just taste good but is also very healthy. And it’s especially tasty when grown at home.
It’s a staple in most vegetable gardens, because it’s quick-growing, and it provides healthy food all summer. A summer salad isn’t the same without homegrown lettuce.
So given its popularity with UK gardeners, we have put together the most commonly asked questions about growing lettuce in the UK, and answered them.
Is It Easy To Grow Lettuce In The UK?
Yes, is the short answer. Firstly, lettuce isn’t too fussed about the soil it’s grown in, unlike many other vegetable plants. Its only requirement is good water retention, as dry soil can cause lettuce to bolt.
To achieve this, make sure you dig in well-rotted organic matter into your beds, such as homemade compost or leaf mulch.
Lettuce doesn’t need particularly high temperatures to germinate, so no need for a propagator, a cool windowsill, or unheated polytunnel or greenhouse will do. And it’s a quick-growing crop: in as little as 10 weeks after sowing, you can harvest.
In terms of caring for your lettuce plants, these are their key needs:
- Plant them out with enough space between plants to ensure good air circulation
- Water regularly, especially in dry, hot weather, to avoid bolting
- Doesn’t need to be fed often, twice during the 10-week growth period is enough
- Keep beds with lettuce in weed-free by hand weeding regularly
As you can see, lettuce is very easy to grow, and is an ideal crop for beginners as well as experienced gardeners.
Learn how to grow lettuce in our handy and detailed guide.
Which Is The Best Lettuce Variety To Grow In The UK?
Well, this depends on your preference. First you have to decide what type of lettuce you want to grow: heartening lettuce or loose-leaf lettuce.
The former is harvested whole, while with the latter you pick individual leaves as and when you need them for a salad or a sandwich. Which one you choose will depend on what you’ll use your lettuce for.
But also on how much space you have. Heartening lettuce needs a bit more space, while loose-leaf lettuce is ideal for growing in containers and small spaces.
Then there is the question of healthiness and flavour. While lettuce in general is healthy, the darker the leaves, the more nutrients they contain.
According to the Senior Lecturer in Nutrition at City, University of London, Dr Swrajit Sarkar, the healthiest variety of lettuce is Romaine lettuce, also called Cos lettuce. It’s packed full of vitamins, minerals, and is a source of fibre.
Little Gem is probably the best-known Romaine lettuce variety in the UK and my absolute favourite. Not just because it’s so healthy, but also because of its taste and texture.
The leaves are crunchy and sweet. Even my husband likes it, and he never liked lettuce when he was younger.
If you’re after a loose-leaf lettuce, my recommendation would be lamb’s lettuce. Not only is it tasty, with a mild, peppery taste, but also super healthy. Lamb’s lettuce is full of vitamins, minerals, fibre and protein, among other nutrients.
In case you’re wondering which lettuce variety has the least nutrients, it’s iceberg lettuce. And in my opinion, it’s also the least tasty of all lettuce varieties I’ve ever tried.
When Is The Best Time To Sow Lettuce?
This will depend on when you want to harvest your lettuce. The good news is that lettuce grows pretty much all year round if you can provide the right conditions.
This means a soil temperature between 2°C and 19°C (36°F and 66°F) for germination and protection from frost as they grow.
The seed packet will tell you when to sow your lettuce seeds, but generally these are the months to sow depending on your desired harvest time:
Harvest In Early Summer
Start sowing your seeds indoors in January or February. As we have said, a cool windowsill will do very well, but an unheated greenhouse or polytunnel will work too.
Once there is no more risk of heavy frosts, which in the UK is late March, but it will depend on where in the country you are, plant the young lettuce plants out.
Make sure you protect them with cloches, or fleece, or under a cold frame. However, during the day, when it’s warm enough, remove the protection for a few hours to ensure adequate ventilation to prevent diseases.
Harvest From Late Summer To Autumn
From March onwards, you can start sowing lettuce outdoors. However, it’s vital to protect the seedlings from frost by covering them with cloches or fleece during the coldest parts of the day and during the night.
Sowing can continue until July to harvest into autumn.
As the weather gets warmer, it’s important to water your lettuce regularly to keep the soil moist. This will stop the plants from bolting.
Continuous sowing during these months will ensure a plentiful harvest throughout the main growing season.
Harvest In Winter
To harvest lettuce in winter, you have to start sowing in August. As it gets colder, from September/October onwards, you have to start protecting your lettuce from frost.
Harvest In Early Spring
In September/October you can start sowing lettuce indoors for harvesting in early spring. An unheated greenhouse, polytunnel, coldframe or a cool windowsill will do.
It’s important to choose the right variety, though, such as Winter Density, which will be more tolerant of colder weather. Crucially, winter varieties will continue to grow in cold weather.
Do You Need To Feed Lettuce Plants In The UK?
Lettuce is a fast-growing plant, so needs a lot of nutrients. Depending on how nutrient-rich your soil is and how well you have prepared the ground, your lettuce plants might need feeding.
Because it only takes a few weeks from germination to harvest, you don’t need to feed lettuce plants very often. Three weeks after germination, and then again about two weeks later.
You want a liquid fertiliser that is high in nitrogen. I have used this seaweed liquid feed and it’s great.
- Boosts Plant Growth & Crop Yields - Natural Seaweed fertiliser that enhances strong & healthy plant growth, promotes lush foliage, and increases crop yields for thriving plants.
- Nutrient Rich Plant Food - Enriched with iron and plant-based amino acids to nourish garden plants, improve soil health, and support plant & root development.
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Or you can make your own homemade liquid fertiliser, which is even better.
It’s also a good idea to add mulch around your lettuce plants. It will suppress weeds and feed your plants slowly. You can buy it or make your own leaf mulch.
You should make sure you water your lettuce regularly, especially during hot and dry periods. Dry soil can encourage them to bolt. This means they set seed and focus on growing flowers and stop growing many new leaves.
That’s not good news if it’s the leaves you are after for your salad.
When Can You Harvest Lettuce In The UK?
You could be growing lettuce in the UK pretty much all year round, which means you could be harvesting lettuce regularly throughout the year.
Loose-leaf lettuce, or cut-and-come-again lettuce, can be ready to harvest in around 6 weeks. It’s important to harvest regularly so the plant keeps growing new leaves. Once a week is about the right frequency.
After the initial harvest, you might get one or even two more, but they’re likely to be smaller ones. If you sow loose-leaf lettuce two weeks apart, you’ll be able to harvest regularly throughout the season.
Heartening lettuce takes a bit longer, around 10 weeks, and winter varieties up to 14 weeks. The head of the lettuce should be firm when it’s ready to harvest.
Top Tip: Don’t leave heartening lettuce plants with firm heads in the ground, otherwise they will start bolting.
The best time to pick lettuce is in the morning, when the leaves are still full of moisture and nice and crisp.
Is Lettuce Susceptible To Pests And Diseases?
Yes, other creatures also like lettuce. And like any other plant, lettuce can also be affected by diseases.
Pests Who Might Nibble On Your Lettuce
Generally, these are the pests that you’ll find feasting on your lettuce plants:
- Slugs and snails – they mostly eat young plants, so protect them until they are safe
- Aphids – use companion planting to repel them (onions or leeks) and/or encourage their natural predators (ladybirds and lacewings)
- Lettuce root aphids – they attack the roots rather than the stems and leaves – keep the soil moist to prevent them from making their home in the soil around your lettuce plants
- Sparrows – they love lettuce, so keep them covered with netting if you have these birds in your garden
Wherever possible, try to tolerate pests. They are part of the ecosystem of your garden and have their role to play. And there is always a way to keep your crop from being ruined without harming any creatures.
Diseases That Might Befall Lettuce Plants
There aren’t many diseases to which lettuce is susceptible. There are only three to keep in mind:
- Grey mould – this fungal disease occurs in humid and cool conditions and can attack all year round
- Lettuce leaf drop – another fungal disease that likes humid conditions and occurs from summer to early autumn
- Lettuce downy mildew – this fungus-like organism occurs outdoors from early summer to mid-autumn and indoors all year round
The good news is that the same measures can reduce the risk of all three of these diseases affecting your lettuce plants.
- Space your plants out well to ensure good air circulation
- Water from underneath so the leaves won’t get wet
- A sunny spot in spring and autumn will ensure the plants dry out quickly in cooler conditions
- Remove affected leaves as soon as you see them and throw them away, but don’t compost them
- Practice crop rotation to prevent the diseases building up in the soil
Does lettuce need full sunlight?
Lettuce is a cool-weather crop, so doesn’t like it when it gets too warm. Early in the season and from autumn onwards, a sunny spot works well.
But during mid-summer, partial shade is better for your lettuce. As too warm weather will cause the lettuce to bolt, which means it produces seeds and stops growing new leaves.
Generally, though, lettuce is not too fussed. My recommendation would be to plant your lettuce in a spot where it gets the morning sun, but is in shade the rest of the day. This will work all year round.
But you want to keep an eye on humidity levels from autumn onwards to avoid diseases like grey mould.
How to grow lettuce in containers?
Lettuce can easily be grown in containers, but make sure that you use a container that is at least 15 cm deep, as its roots are quite long.
The container, pot or grow bag you use should have plenty of drainage holes to allow excess water to run off.
Try not to cram too many plants into one container, though, as this will prevent air from circulating. And this is important to avoid fungal diseases. Always thin out your seedlings.
Water your lettuce regularly when growing in containers or bags to prevent the soil from drying out, as this can cause the plants to bolt and also increases the risk of lettuce root aphids infesting your lettuces.
You can use multipurpose compost. Fill the container full to the brim, then water well. Watering before sowing the lettuce seeds will ensure that you don’t wash them away.
Sow the seeds thinly, then cover them with a thin layer of compost and lightly tap the soil. Keep the surface of the soil moist until the seedlings have grown their first true leaves. The best way to do this is by spraying the surface with water, rather than watering with a watering can.
Once the seedlings are stronger, thin them out and start watering them directly at the soil, rather than from above, to keep the leaves as dry as possible.
Harvest cut-and-come-again varieties as soon as the leaves are big enough and lettuce heads when they are firm.
If you don’t have much space, but want the taste of fresh lettuce, you can grow loose-leaf lettuce varieties in window boxes. Again, make sure you water them regularly.
Can I grow lettuce indoors under lights?
Yes, you can. But you will need a good grow light that is made for the purpose of growing plants. Because plants need certain wavelengths of light to be able to photosynthesise, such as the blue and red ranges.
Therefore, growing lights can be expensive. For an experiment, I tried this grow light, which wasn’t too expensive and it worked well.
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- 【Optimal Full Spectrum】Different from others, this led grow light added 2PCS Yellow LED, is beneficial to the synthesis of photosynthetic pigments, promoting energy transmit, improving plant growth quality. It also has universal Blue, Red, IR, UV, White light. Blue and red led are an essential light for all plant growth. Expensive IR UV led can promote plants to defense mechanisms.
- 【Wide Coverage】60PCS SMD led(total 600W) provides uniform illumination. It can replace traditional 600-watt HPS/MH while consumes only 80 watts. Ensures maximum yield with minimum power usage and heat. PAR 436umol/m2s at 24” height, perfect for 2x2ft growing area(Maximum coverage area at 4x4ft at 24” height).
Can I grow lettuce without soil?
It’s possible to grow lettuce and any other plant without soil. Plants need air, water and nutrients to grow. Soil provides these things, and that’s why it’s used.
But as long as you can create an environment that provides the roots of a plant with these three elements, you don’t need soil. There is a science looking into this called hydroponics.
An easy way to grow plants without soil is to plant them in a pot with perlite and water them regularly with water containing a liquid fertiliser. The air is held between the perlite, which will ensure the roots won’t suffocate.
As long as you don’t let the perlite dry out, the plant should grow, in theory. As I said, hydroponics is a science, so it isn’t easy to do.
You can buy hydroponics growing systems that let you grow vegetables and herbs without soil. Most of them include a growing light, so you can grow your plants anywhere. Like this one, for example.
- 20% Faster than Soil Planting: Hydroponics growing system built-in a low-noise pump, circulating the nutrient solution absorded by the roots direactly. And built-in a fan which spreads pollen in florescence, disperses heat in germination
- 4.5L Water Tank with Visual Window: The water tank of this indoor garden is 4.5L, and can support plants to grow for 1-2 weeks in the growth period. A visual window can see how much water in tank
- Easy-Setup Germination Kit: 3 steps in all to set up the hydroponic growing system machine. All the factors needed for plant growth - light and simulated soil are included in the hydroponic growing system
It sounds like a very fancy idea, and if you don’t mind spending the money, it is probably worth a try. If you want to learn more about how to grow lettuce without soil, you can find out how to set up a hydroponics system on wikiHow.
Hopefully, you have found the answers to all your questions about growing lettuce in the UK. It’s very easy and you don’t need much space, so give it a go. Happy Growing!
