Do you want crispy lettuce all year round? The good news is, growing lettuce is easy and will grow most of the year.
With some planning, regular planting, and correct variety selection, it’s possible to grow lettuce all year round. With the protection of a greenhouse, cloche, or fleece, you can have lettuce growing into the coldest winters.
Most lettuce is ready to begin harvesting in 50 days, with cut-and-come-again or leaf lettuce varieties often ready far sooner than this. Succession sowing is essential.
When it comes to taste, homegrown lettuce is often sweeter, crunchier, and juicier. And lettuce is also really healthy, as it’s packed full of vitamins, including A and K, but also a source of fiber and plant-based protein.
In this article, we’ll show you how to grow lettuce in your garden.
Choosing Which Variety To Grow
Before we start teaching you how to grow lettuce, let’s look at some varieties we would recommend.
There are a lot of varieties of lettuce available, so choosing the right one for you is important. There are two different types: heartening lettuce and loose-leaf lettuce.
The main difference between the two types of lettuce is the way they grow their leaves. Heartening lettuce grows a lettuce head or heart where the leaves are layered on top of each other. Loose-leaf lettuce, as the name suggests, grows more loose leaves, which means you can harvest individual leaves as you need them.
- Heartening lettuce is divided into three types:
- Cos lettuce, sometimes also called Romaine lettuce: this type grows into oblong lettuce heads, such as Little Gem lettuce
- Butterhead lettuce: this type produces a more open shape, such as the All Year Round lettuce
- Crisphead lettuce: this type has a large heart with curled, crisp leaves, such as the classic Iceberg lettuce
Loose-leaf lettuces come in a variety of shapes, flavours and colours. And while the choice of the type of lettuce you grow is down to your own preference, loose-leaf lettuces are more suitable for small spaces and growing in containers.
To make your choice easier, our guide about how to grow lettuce shows you some favourite lettuce varieties for you to try:
Little Gem: this well-known lettuce variety is a cos type and produces sweet and crunchy leaves in a very compact head.
Salad Bowl: this non-hearting lettuce variety produces green leaves and will give you salad all summer long.
All Year Round: this butterhead variety is great for sowing all year round.
Lamb’s Lettuce: another loose-leaf variety, which is also known as corn salad, has a mild flavour.
Preparing The Ground
While lettuce plants aren’t very fussy about soil conditions and are generally a tolerant crop, they need a constant supply of water, so water retention in the soil is important.
Dry soil can cause the lettuce to bolt, which means it starts to produce seeds. Once this happens, they will put all their energy into growing the seeds rather than the leaves, which will stunt your yield.
You want to prepare the ground about two weeks before you sow your lettuce seeds or plant on your lettuce seedlings.
Mix your garden soil with well-rotted garden compost, shop-bought compost, or blood, fish, and bone fertiliser to add vital nutrients. I have used this one before and was very happy with it.
- Can be applied to all plants and crops & spread by hand or fertiliser spreader
- Provides major nutrients needed for strong and healthy growth
- Active Ingredient: 5% nitrogen, 5% phosphate & 6.5% potassium
Or use your own homemade compost or leaf mulch, which will both work a treat, and it’s free.
When & How To Sow Lettuces
Lettuce is a cool-weather crop, as its ideal germination temperature is between 2°C and 19°C. Lower soil temperatures will slow down germination, whereas if your soil temperature is higher it will decrease the chance of germination.
Your seed packet will tell you when to sow your lettuce seeds, but here is a general guide of timings:
- January/February: sow indoors in seed trays to harvest in early summer
- March – July: main growing season; sow outdoors, but protect your lettuce plants from hard frosts, for example, with cloches, in early spring. From late March on, you can also start to plant on your lettuce seedlings you started off indoors
- August: sow outdoors for winter harvest; protect your plants with cloches when the weather gets colder, normally from September onwards
- September/October: sow indoors to harvest in spring; make sure you choose suitable varieties for winter harvest, such as ‘Winter Density’
Seeds should be sown just less than half an inch (1cm) deep and covered with a thin layer of very fine soil or compost.
Spacing for lettuce depends on the type grown. Leaf lettuce should be about 4 inches (10cm) apart, cos and loose leaf varieties should be 8 inches (20cm) apart, and large icebergs should be 12 inches (30cm) apart. For winter planting, increase these spacings by at least 2 inches (5cm) to allow for extra airflow and prevent any mould or rot.
Rows should be 12 inches (30cm) apart, but for small plants or in good soil can be planted closer.
It’s important to keep sowing lettuce regularly to achieve a continuous crop. Growing a few different varieties will ensure your harvest dates vary and cropping is extended. This is the secret of how to grow lettuce almost all year round.
In spring, making new sowings every 2 weeks will keep the lettuce leaves coming, while more slow-growing winter varieties should be sown monthly. This will guarantee you a steady supply of salad!
How To Grow Lettuce Plants On
Let’s move on to the next step in our guide about how to grow lettuce.
If you have grown your lettuce from seed in trays, then your seedlings will be ready to transplant when the first true leaves appear. True leaves are the second pair of leaves that grow. They resemble the look of the adult plant’s leaves.
The first leaves that grow from a seed are called seed leaves, and they are not able to perform photosynthesis, the way plants produce food for themselves.
In terms of timings, you can plant out your seedlings once heavy frosts are over, normally later March.
Lettuce is not really fussy about the soil it is grown in as long as it’s reasonably good. Being fast-growing, lettuce really likes to get a lot of its food from liquid fertilisers. A general-purpose feed or a good mix of liquid seaweed 3 weeks after transplanting and again after 5 weeks will give incredible growth.
I have used this seaweed feed regularly for most of my vegetable plants.
- 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.
- Versatile & All Purpose - Ideal for lawns, fruits, vegetables, flowers, trees, and all other garden plants. Perfect for any outdoor or indoor plants.
If you expect to harvest within 7 days, do not feed.
It’s important to keep lettuce plants well ventilated when they are in a greenhouse, cloche, or under fleece. During warm days, remove the plants’ protection for a few hours to allow fresh air to circulate around the plants.
Weeding of lettuce should really be done by hand once every two weeks. Small weeds should pull from the soil by hand easily and won’t damage the lettuces’ shallow roots.
Make sure you water your lettuces regularly, especially in hot weather, to avoid the soil getting too dry, as this will cause them to bolt, i.e. produce seed. In hot weather, the best time to water your plants is early morning to give the water chance to reach the lettuce roots.
Apart from regular watering, you can also help the soil keep the moisture in by covering the area around your lettuce plant with mulch. This will also feed your plant, Hurray!
If you have sparrows in your area or garden, then make sure you protect young lettuce leaves from them. They absolutely love them! You can cover them with fleece or garden netting.
Harvesting Lettuce
Now we come to the best part: harvesting! Harvest your plants regularly.
Cut-and-come-again lettuce should be picked weekly. Once the plants begin to look tired, another sowing should take over. Cut-and-come-again lettuces grow quickly, so multiple sowings a year can be made in the same ground.
It’s easy to tell when head lettuce is ready by squeezing the lettuce to see if the head is firm. Once the head is firm, do not leave in the ground more than another week or two, as they will quickly bolt and go to seed.
After harvesting if you quickly place the lettuce in a plastic bag in the fridge, it will often last a week to ten days. Cut-and-come-again types will usually wilt faster, so should be eaten within 5 days. Long-term storage of lettuce isn’t possible.
The best time to harvest lettuce is early in the morning, before the leaves lose some moisture, which will make them less crisp.
Pests and diseases affecting lettuce
While lettuce is fairly easy to grow, it is susceptible to some pests, including aphids and some fungal diseases. And no guide about how to grow lettuce would be complete without mentioning these.
Pests
Slugs and snails love crispy and juicy lettuce leaves. Clearly, they have good taste! So, to tell you how to grow lettuce successfully, I have to tell you about slugs and snails.
They are often described as ‘gardeners’ enemy number one’ because most plants in our gardens, not just vegetables, are on their menu.
However, slugs and snails are vital for our ecosystem, so wherever possible, try to tolerate them. Don’t use slug pellets, as they kill them and can also affect other wildlife.
Of course, you don’t want them to ruin all your hard work and keep you from enjoying delicious salad, so here are some tips to keep your lettuce safe from slugs and snails:
- Slugs and snails mainly eat young plants, so you can protect your lettuce seedlings by covering them with cloches until they are big enough not to attract too many slugs and snails.
- Companion planting: there are plants that slugs and snails don’t like and will avoid. So if you plant these plants around your lettuce, they will be safe. These plants include lavender, rosemary, and sage. To find out more about companion planting, read our complete guide on companion planting for vegetables in the UK.
- Harvest your leaves as soon as they are big enough to eat and lettuce heads as soon as they are firm.
- If you spot a slug or snail on your lettuce, pick it up and move it to a part of the garden where it cannot do as much damage. I have a wild area in my garden, where slugs and snails are welcome. The best time to do that is a couple of hours after dusk. You might need to use a torch.
Another pest that might affect your lettuce plants is lettuce root aphids. Unlike other types of aphids, these feed on the lettuce roots rather than the leaves or stems. This means you won’t see them above ground. They are most active in mid- to late summer, and signs that your lettuce suffers from a root aphid infestation are:
- Your adult plants suddenly wilt and die
- Like other aphids, these are also ‘farmed’ by ants, who like to drink the honeydew the aphids produce. So if you notice a lot of ants around your lettuce, root aphids might be in the soil
When it comes to aphids, prevention is the most effective thing to do, especially when they are underground and therefore not visible above ground. Here are some tips on how to prevent an aphid attack on your lettuce roots:
- Root aphids prefer dry conditions, so regular watering, especially in dry weather, will minimise the risk of an infestation.
- If you think your lettuce is affected, you can carefully pull out the plants and check their roots. Make sure to only pull out plants that are big enough not to get damaged by this. If you see any aphids, wash them off with water. Then replant the lettuce in fresh compost, never in the same place, as the aphids will be in the soil. Cultivate the soil to expose the aphids, which will make them an easy meal for natural predators such as ladybirds.
- You can also use insect-proof mesh to prevent the aphids from reaching the lettuce roots. I used this Environmesh before, and it worked well.
- PROTECT: Protect your vegetables and soft fruit from a range of insect pests, birds, rabbits and the weather
Diseases
Grey mould is a fungal disease that often affects damaged plants, which have cuts or tears. It favours humid conditions and can occur all year round.
You will see a fuzzy grey-brown mould developing on the leaves. Any infected leaves should not be eaten. Destroy them as soon as you see them, but don’t compost them. If the stem is also affected, the plant will turn yellow-brown and develop into slimy rot.
Here are some tips to prevent grey mould from affecting your lettuce plants:
- Grey mould thrives in humid conditions, so ensure good air circulation by planting your lettuce well spaced out.
- Water from underneath to avoid the leaves getting wet and water in the morning
- Later in the season, if you grow your lettuce outdoors under cloches to protect them from frost, make sure you remove the cloches during the day in warm weather to reduce the risk of humidity. If you grow in a greenhouse, keep it well ventilated, even in cold weather.
- The fungus enters most easily through cuts or tears, so try to keep slugs and snails away from your plants to avoid damage
- If you spot any signs of grey mould, remove the affected leaves immediately and destroy them, do not compost
- Keep the area around your plants free from dead plant material to minimise the risk of grey mould affecting your plants.
Leaves infected by grey mould are inedible. If you remove the outer leaves of a lettuce head as soon as you spot any signs, the rest of your lettuce should still be good to eat. But check for signs after you have removed any infected leaves to be sure.
Another fungal disease that can affect lettuce is lettuce leaf drop. It is most prevalent from summer to early autumn and favours wet soil conditions. Symptoms of lettuce leaf drop are when a plant suddenly turns yellow, wilts, and collapses, and on the underside, you will see a soft white mould develop. You might also notice the smell of rot.
Heavily infested plants cannot be eaten!
Here are some ways to minimise the risk of lettuce leaf drop affecting your plants:
- Space your plants well apart to ensure good ventilation and plant them in a sunny spot to prevent humid conditions
- Weed regularly around your lettuce plants, ideally by hand, to help the area dry quicker after rain
- Mulching your plants can help minimise mud splashing on the leaves when it rains
- Water your lettuce from underneath, to avoid the leaves getting wet
- Practice crop rotation as the spores can overwinter in the soil, which will then affect next year’s plants
- Remove any infected plants and destroy them, but do not compost them, as the spores can survive and infect your compost
Lettuce downy mildew is a fungus-like organism that affects lettuce. Infected plants develop yellow patches and white mould on the underside of the leaves. The plant will turn brown as the leaves die.
The disease is active outdoors from early summer to mid-autumn, but indoors it can strike all year round. A plant infected with lettuce downy mildew can also attract grey mould.
Like with most diseases, prevention is the best way to keep your salad safe:
- Ensure good circulation of air as humidity encourages downy mildew
- A sunny position will ensure the leaves dry out quickly after rain
- Practice crop rotation to avoid any spores that overwintered infecting new plants
- Remove any infected plants immediately. Often the disease only affects the outer leaves, leaving the rest of the lettuce head unaffected and therefore good to eat. Remove the entire plant once you have harvested the lettuce heads to avoid the soil getting infected, which could then spread to other lettuce plants
Luckily, many ways to prevent one disease also prevent the others, so keeping your lettuce disease-free is not too much work.
Now that you know how to grow lettuce for almost a year round harvest, you can look forward to delicious and vitamin-rich salads!
