How To Get Started Growing Lettuce In Containers

Growing lettuce in containers is one of the easiest vegetables for container gardens. Lettuce grows well in small spaces, and you can have fresh salads all summer long if you have space for just a few pots.

Not all vegetables grow well in pots, but lettuce doesn’t have deep roots, nor is it too large. That makes it the perfect candidate.

It takes no time to get a harvest; for most varieties, it takes only eight weeks from planting to harvesting.

If you grow cut-and-come-again lettuce types, then you’ll have fresh lettuce available all the time!

How easy is it to grow lettuce in containers?

To grow lettuce in containers choose a pot that is 6 inches deep filled with well-draining, high-quality potting soil.
You can either use transplant – bought at a greenhouse or started indoors at your home – or plant seeds directly into your garden beds.
Start planting 2-4 weeks before your final frost date and continue to sow a new row of seeds every other week during the growing season.
Harvest as soon as the leaves are the size that you hoped they’d become

When you’re growing lettuce in containers, you have quick access to fresh salads, and it doesn’t take that much work.

From picking your pot to planting the seeds and watering correctly, this guide shows you everything, you need to know about how to grow lettuce in containers. This is a perfect gardening task for new growers.

Growing Lettuce in Containers: How to Get Started

If you’re a new gardener, don’t worry. Lettuce is one of the easiest plants to grow. It doesn’t require any special tricks to make it grow. It’s as simple as planting the seeds and letting it grow.

1. Decide Where To Put Your Pots

It’s a bit tricky to pick the right spot to put your container lettuce. While they’re a sun-loving plant, lettuce also struggles with too much sunlight and heat.

Pick an area that has full sunlight, but you also can pick a partially shaded area. If you have a spot in your garden that receives morning sunlight but has shade in the afternoon, that works well for lettuce.
Warm climate gardeners need to ensure their lettuce does have shade throughout the day.
During the hottest hours of the day, try to create some shade for your plants to stop the soil from drying out thoroughly. This can be a canopy or a trellis that casts shade throughout the day.
If all else fails, you can move your container to a cooler spot when the temperature gets too hot for your lettuce plants.

2. Pick The Right Container

Since lettuce doesn’t have deep roots, you can select wide, shallow containers. Window boxes are a great option, so long as the containers are 6 inches deep or more. If you want to use a circulator pot, make sure it’s 10-12 inches in diameter.

You need to make sure that the container you select has a few drainage holes in the pot’s bottom. Lettuce will rot if left in standing water.

You can pick pots that are made of clay, terracotta, or plastic. They all are excellent choices for lettuce plants. However, if you live in a warm climate, make sure you use clay pots and grow heat resistant varieties.

Clay pots are considered to be the best choice for growing lettuce because they have a porous surface. That allows excess water to evaporate, which helps to stop the roots from becoming soggy.

3. Fill Your Containers With The Best Soil For Lettuce

To grow the best lettuce plants possible, it all starts with the right soil. Soil is the feed for your plants.

With poor soil, lettuce plants grow, but they might not reach their full potential. Chances are you want your lettuce plants to be full and thrive.

Fill your pots with a good quality soil mix that contains organic matter. Look for a blend that contains material like perlite because it provides drainage and proper aeration.
Be sure to mix compost and/or peat moss. Another option is well-rotted manure.
It’s also vital that the soil you use is loamy and well-draining. You cannot plant lettuce in soil that holds too much water.
If you don’t want to fertilize throughout the growing season, look for a potting mix that containers a slow-release fertilizer already added to the soil. Then you can plant your lettuce seeds and forget about feeding for the rest of the growing season!
Fill your pots almost to the top, leaving 1-2 inches of space. You don’t want the soil to wash out over the sides when you water.

4. Know When To Plant Lettuce

Lettuce is an early spring and cool-season crop. While it can survive the heat of the summer, you’ll get the best growth during the spring and the fall. However, lettuce grows best in the winter if you live in subtropical or tropical parts of the world.

Lettuce seeds struggle to germinate if the soil temperature is warmer than 75℉. At the same time, it cannot be covered in frost.
If you want to start earlier than recommended, you’ll need a cold frame or a frost blanket to cover your garden beds.

You should plan to plant your first lettuce seeds 2-3 weeks before your final frost date.

While you’re still vulnerable and might have a few more frosts, at this point, the danger of a hard frost has passed.

Greens can tolerate a light frost, but a severe and hard frost will kill your lettuce plants.

Then, you can use succession planting and plant a new row every two weeks following your first planting. Do this until eight weeks before your final frost date.

Using this technique can help you grow more lettuce and not waste what you have available. The harvesting time will be staggered rather than all of your lettuce coming up for harvest at one time.

5. Decide If You Want To Sow Seeds Or Start Transplants Indoors

Unlike other crops, you can grow lettuce from both seeds and transplants. You can start transplants indoors at your home or buy them from your local greenhouse.

If you decide to go with the options your local nursery has, you’ll have a smaller selection.

If you want to start seeds indoors, sow them in flats or starter trays 3-4 weeks before you want to transplant them outside.

Fill your flats or trays with a seed starting mix.
Sow the seeds ¼ inch deep and then water them deeply.
Keep your flats somewhere that is cool – around 65℉ works great. If you keep them somewhere warmer than 75℉, the seeds might struggle to germinate.
Continue to keep the soil damp, but make sure it’s not soaked or soggy. Once the seeds germinate, they need to be kept under grow lights or fluorescent lights. Lettuce seeds can also grow in a sunny part of your home if they receive enough light.
Don’t let the soil dry out; seedlings have small root systems so they cannot access water at the bottom of the tray.
If possible, keep a fan near the seedlings because proper air circulation is vital. A small room fan can increase air circulation. You only need to run it for 15-20 minutes per day to provide the aeration necessary.
Before you plant your seedlings outside, they need to be hardened off. Typically, you’d start this process 3-4 days before your planned planting time. The first day, you’ll take the seedlings outside for an hour or two then bring them back inside. Each day, you expose them for more extended periods outside until they are used to the sun’s strength.

6. Plant Lettuce In Your Garden

First, we’re going to cover planting lettuce from seeds, then how to plant transplants.

Sow your seeds densely, ¼ to ½ inch deep. Then, cover the row of seeds lightly with soil. The soil needs to stay moist until germination takes place.

As the seeds sprout and start to grow, thin out the seedlings, picking the tender, young leaves. Don’t toss those out! Young leaves can be tossed into salads.

Most lettuce varieties are cut and come again, so spacing doesn’t matter too much. You’re going to harvest regularly, and the sizes won’t get out of hand.

When you start to thin the seedlings, keep the plants 4-6 inches apart, depending on how large you want the leaves to be when you harvest.
Head lettuce varieties need more spacing than leaf lettuces. You also need to increase the depth of the seed. Plan to thin the seedlings to 8 inches apart.
Larger varieties of crispheads need to be spaced 12-18 inches apart.

If you’re planting transplants, you won’t thin anything. Instead, measure out the appropriate distance between your plants and dig a hole that will fit your transplant.

Take the seedling out of its container, loosen the roots gently with your fingers, and place it in the hole.

Fill the rest of the hole in with the soil and firm around it with your hands. Do this until your pot is full.

Make sure you water thoroughly to help establish your plants in the soil. You want your plants to start growing as soon as possible!

7. Consider Adding Companion Plants To Your Container

Did you know that you can add more than one type of plant to your container? If you have a large enough container, you can try adding some companion plants.

Companion planting is when you add mutually beneficial plants together; they help each other grow by either deterring pests, trapping pests, or improving the soil.

Some companion plants for lettuce include:

Radishes
Cucumbers
Spinach
Parsley
Violas

How to Care for Lettuce Growing in Containers

Lettuce doesn’t require a lot of upkeep and care, but knowing what your plants require will ensure you get the most out of your plants. Here is what you need to know.

1. Water Your Plants Frequently

Lettuce plants are cool-season crops, so like so many other greens, they do require a lot of water. Lettuce is 95% water!

Dry soil will cause your plants to wilt, but at the same time, you don’t want standing water, which will lead to your crops rotting.

Since you’re growing in containers, you need to check daily to see if your plants need to be watered.
Put your finger into the soil to see if it’s dry 2 inches down. If it is, it’s time to water. If it’s still damp, you can wait to water until later that day or tomorrow.
Overwatering container-grown lettuce is just as dangerous as overwatering because of root rot. Don’t water too much.

2. Boost Growth With Fertilizer

You’ll quickly realize that lettuce plants grow fast. You shouldn’t fertilize immediately. Give it several weeks; the seedlings need time to establish and start growing.

After 4-5 weeks, it’s time to apply fertilizer to continue the quick rate of growth

Use a balanced granular fertilizer, such as a 10-10-10.
Liquid fertilizer is an option if you want to give your plants a quick boost. Always follow the manufacturer’s instructions because over and under fertilizing can be harmful to your plants.
You might need to fertilize more than one time throughout the growing season. Watch your plants! If you notice that their growth rate starts to slow down, it’s time to reapply fertilizer.

3. Avoid Bolting

Lettuce has the tendency to bolt, which is when a crop prematurely matures and starts to produce seed. If lettuce bolts, it can cause the leaves to develop a bitter taste that is far from appealing.

While you can try planting bolt resistant varieties, there are also a few things you can try to decrease bolting ruining your crop.

Plant your crop as early as possible, even if that means sowing seeds in a cold frame or undercover.
Use succession planting to avoid not harvesting quickly enough.
Make sure you frequently water the plants. If they start to wilt and dry out, they can quickly go to bolt.
Remove the pots from the late afternoon sun to keep your crop as cool as possible.
Lay down mulch on the soil, especially an organic mulch such as grass clippings or compost, to keep the soil as cold.

4. Keep The Container Weed Free

Weeds compete with your lettuce plants for nutrients, so you want to remove all the weeds that you can.

Keeping the soil weed-free is crucial, but they’re fast to emerge. Make it a daily task to pick any weeds that you see.

Common Pests & Diseases That Bother Lettuce Plants

One of the bonuses of growing lettuce in containers is that you have fewer pests and diseases to deal with in your garden.

The biggest problem you might face is leaf-eating insects. If you keep your plants healthy, you will have a lower risk of infesting pests or diseases.

Powdery Mildew

This fungal growth looks like a white powder covering the top and undersides of leaves. The leaves sometimes turn yellow or brown. Typically, powdery mildew shows up during humid weather conditions.

You can try to manage powdery mildew by applying sulfur as soon as you notice signs.

Leaf Drop

If you notice outside leaves starting to wilt, slowly affecting the whole plant or soft watery lesions on the leaves, you might have leaf drop. This is a fungus that lives in the soil for years.

Unfortunately, there is no treatment, but you can try to reduce it by rotating crops. You can try to reduce it by applying fungicides after thinning plants.

Aphids

Without a doubt, aphids are the most common pest that you need to deal with if you’re growing lettuce in containers.

Aphids are tiny insects that love to stick to the leaves’ underside, feeding on the plant. They can be green, brown, orange, red, or white.

In most cases, aphids don’t severely harm your plants, but if enough gather on your plant, they could decrease your harvest.

Make sure you always wash your lettuce leaves thoroughly to avoid aphids in your salad.

You can wash away aphids with a blast of your hose or applying soapy water to your plants. If the infestation becomes too bad, you can use insecticidal soap to get rid of them.

Slugs

Another pest that you might struggle to handle is slugs. Slugs love lettuce – who can blame them – and they can do a lot of damage quickly.

You can try to put crushed up eggshells around your plants to discourage slugs from visiting.

You also can make beer traps to protect your crops, or try wrapping copper tape around the container to stop pests from getting access to your vegetables.

Harvesting Lettuce

How you harvest lettuce growing in containers varies based on what type of lettuce you’re growing. There is no set time that you need to harvest lettuce. You can start when the leaves are small or when they’re larger. It’s up to you to decide.

Lettuce leaves are ready for harvesting when they’re 4-6 inches tall, which is the perfect size for the cut and come again method.
You can either pick the outer leaves individually or harvest the entire plant. If you want the plant to come back again, you need to leave 1-2 inches remaining at the base of the plant.
If you cut too low or below the crown, your plants will die.
Picking leaf lettuce can be done before maturity as well. Remove the outer leaves whenever you want to eat a salad, and the center leaves will continue to grow.
If you do want a full-size head of lettuce, let the plants grow until they reach maturity. Then, cut them off right at the base, above the soil line.

The best time to harvest lettuce is in the early morning because the leaves have peak moisture content. While you might want to wait until dinner is closer to harvest, the leaves taste better when picked in the morning and won’t be wilted.

The Best Varieties of Lettuce for Container Gardening

Thankfully, almost every variety of lettuce grows well in containers, so you have the freedom to pick whatever you like the most.

There is an endless selection of lettuce to grow. First, you need to pick the type of lettuce you want to grow and then the variety from that type.

Let’s go over the types of lettuce and a few different choices for each one!

Butterhead

Do you want loose heads with soft, buttery leaves that melt in your mouth? If so, butterhead lettuce is for you. These leaves are mild and sweet, with a delicate flavor that is slightly addicting.

Bibb Lettuce
TomThumb Lettuce
Blushed Butterhead
Flashy Butter Oak

Crisphead

With this name, you might guess what it forms large, firm heads. It’s very similar to the lettuce you can find in the store that has round, large, firm heads.

The most popular selection is iceberg lettuce – that name should be familiar to you!

While these are some of the most commonly grown types, there are a few problems.

Crispheads prefer cool temperatures, so you shouldn’t attempt to grow these in the summer or if you live in warmer climates. Also, they are the hardest type to grow in pots, taking the longest time to mature.

Igloo
Hanson Improved
Crisphead Great Lakes

Loose Leaf

If you’ve never grown lettuce, loose-leaf lettuce is one of the easiest kinds to grow. It doesn’t form into a tight head that you might imagine or what you find in the grocery store.

One of the biggest reasons, aside from the easiness, is that loose-leaf lettuce has the quickest maturing varieties.

You only need to wait a few weeks to have fresh lettuce on your dinner plates, some only taking 45 days to harvest. If patience isn’t your virtue, go with this type!

Loose-leaf lettuce tends to have a mild flavor, but it is stronger than a butterhead. You can find some cultivars that tolerate hot weather, growing a wider range of USDA zones.

Deer Tongue
Grand Rapids
Prizehead
Green Ice
Red Sails

Romaine

Most people are familiar with romaine lettuce; it’s typically used in salads served at restaurants or your favorite Caesar salad.

Romaine lettuce is known for growing in an upright habit that differs from other lettuce varieties. It has sturdy, crisp leaves rather than the soft ones.

Romaine lettuce tends to produce leaves that form around a tight center. It builds into a loose ball or an oval shape, depending on what you select. Most varieties take around 85 days to reach maturity, and it can tolerate some heat.

Cimarron
Vivian
Paris White
Little Gem

Get Started This Year!

Hopefully, even if you’ve never grown a vegetable in your life, this guide showed you that growing lettuce in containers is way easier than you imagined.

Lettuce grows well in containers, and you’ll have fresh lettuce for salads all year round. Give it a try this year; you won’t regret.it.

Written By

Amber Noyes

Amber Noyes was born and raised in a suburban California town, San Mateo. She holds a master’s degree in horticulture from the University of California as well as a BS in Biology from the University of San Francisco. With experience working on an organic farm, water conservation research, farmers’ markets, and plant nursery, she understands what makes plants thrive and how we can better understand the connection between microclimate and plant health. When she’s not on the land, Amber loves informing people of new ideas/things related to gardening, especially organic gardening, houseplants, and growing plants in a small space.