How to Grow Lettuce From Seed: A Beginner's Guide to Fresh Homegrown Salads

Lettuce is one of the easiest vegetables to grow and is perfect for beginner gardeners. Lettuce seeds are quick to germinate, and the leaves grow fast. Within six weeks, you can be picking leaves for a crisp salad. Follow these simple steps to start growing fresh lettuce in your home garden.

• Sow seeds 3-4 weeks before the desired transplanting date.

• Use growing cells and plant 2 to 3 seeds per cell.

• Plant seeds ¼” deep in seed starting mix.

• Use a spray bottle to moisten the soil.

• Keep the seeds moist until they germinate in 7-10 days.

• Once seedlings are large enough, they can be transplanted outdoors. Lettuce seedlings should be several inches tall with multiple leaves.

• Before transplanting them outdoors, take 2 or 3 days to harden off lettuce seedlings.

• Lettuce seeds can be sown outdoors as soon as the soil is workable.

• Soil temperature of 50-65ºF is the optimal range.

• Plant seeds ¼” deep in fertile, well-draining soil.

• Keep soil moist but not waterlogged.

• Thin lettuce seedlings to 8-10 inches apart.

Lettuce grows best in moderate temperatures, which makes it a popular choice for spring and fall gardens.

In our spring garden, lettuce will be the first thing we sow. We recommend it to all first-time gardeners.

We sow lettuce seeds in our fall garden and enjoy a fresh harvest until the first freeze.

Lettuce seeds can be started indoors and then transplanted or sown directly outdoors. The benefit of starting lettuce seeds indoors is that you can protect the tender seedlings from extreme temperatures. 

For a fall crop, you can start lettuce seeds indoors in late summer and then transplant them after the last heat wave. In the spring, you can have lettuce seedlings ready to be transplanted outdoors when the temperatures are ideal.

Lettuce plants are easy to grow and maintain. They are the perfect crop for beginner gardeners and can be grown in small spaces.  Even if you only have a balcony, you can enjoy the delicious taste of crisp, homegrown lettuce. Follow these lettuce growing basics for a successful fresh harvest.

Lettuce can be grown in full sun when it’s not too hot. But some shade will help to keep it cool. Lettuce will need at least 6 hours of sunlight daily.

Rich, fertile soil that drains well is the best for growing lettuce. Keep the soil consistently moist. We like growing lettuce in our raised beds. This also helps to keep out the rabbits. You can amend your soil with well-rotted compost before planting.

Water lettuce at the root area while aiming to keep the leaves dry. Drip irrigation works well for watering lettuce. Lettuce typically needs 1 inch of water per week. However, more frequent watering may be required in dry climates or sandy soil.

Lettuce grows fast and doesn’t usually need fertilizer when grown in nutrient-rich soil. Nitrogen does help leaves grow, and a slow-release fertilizer can be added to the soil before transplanting.

Lettuce seeds are so tiny that it’s difficult to space the seeds far enough apart. Thinning the seedlings to a proper spacing will give them room to grow without competition. Cutting these tender plants with small scissors is the best way to thin them. This will prevent disturbing the other plant roots. Space lettuce plants 8 to 12” apart, depending on the variety.

Succession planting every 2 to 3 weeks is an excellent way to lengthen your lettuce harvest. You’ll have enough leaves to harvest each week without having it all at the same stage at the same time.

Lettuce companion planting can be beneficial in several ways. One benefit of companion planting is to control pests. Sweet alyssum and other flowers will attract beneficial insects that eat aphids. Another advantage of companion planting is to provide lettuce with shade and soil nutrients. Planting lettuce with tomatoes, pole beans, and other crops can give them shade as they grow. Legumes add nitrogen to the soil and make great companion plants.

As the summer garden slows down, you can interplant lettuce. You can intercrop lettuce plants when you remove warm-weather crops that have stopped producing. These cool-weather crops will fill the space and appreciate the lower temperatures.

Poor germination is often caused by dry soil, old seeds, planting seeds too deeply, or excessively warm soil. Keep the soil moist until seedlings emerge, between 7 and 10 days. 

Sow seeds just 1/4 inch deep and use fresh seed. While lettuce seeds can remain viable for several years if stored properly, germination rates gradually decline with age.

Is there anything aphids don’t attack? Aphids are tiny insects that gather on the undersides of lettuce leaves and new growth. They feed by sucking plant sap, which can weaken plants and leave behind a sticky residue. 

Since lettuce is eaten fresh, using natural methods to fend off aphids is important, as you don’t want to put toxic chemicals on something you eat fresh.

A strong spray of water, insecticidal soap, beneficial insects, and removing infested leaves are all effective ways to control aphids.

Slugs and snails are common lettuce pests because they thrive in the moist environment with leaves close to the ground. They chew irregular holes in leaves, often feeding at night.

To keep slugs and snails from destroying your fresh lettuce, hand-pick pests at night or in the early morning. Also, transplanting lettuce seedlings will give you a growing head start before slugs and snails find them.

Rabbits absolutely love lettuce! If lettuce leaves seem to disappear overnight with clean, angled bites, rabbits are often the culprit.

Placing physical barriers around your lettuce patch will be the best rabbit deterrent.

Fungal diseases such as white mold and powdery mildew can develop when humidity is high and air circulation is poor. 

You can help prevent fungal diseases by spacing plants properly, watering at the base of the plant early in the morning, and removing infected leaves or plants promptly.

Hot, dry summers will eventually take their toll on lettuce. When temperatures rise above 80ºF, lettuce naturally begins to bolt, sending up a flower stalk and producing seeds.

Once bolting starts, the plant stops producing new leaves. At this point, the lettuce leaves become bitter and develop a bitter milky sap.

Keeping plants cool and shading them can prevent lettuce from bolting too soon. Once a plant has bolted, it's best to remove it. You can wait until fall to plant your next crop of lettuce.

There are different ways to harvest lettuce depending on whether you are growing head or leaf lettuce.

Head Lettuce vs. Loose Leaf Lettuce

Head lettuce grows leaves in a tight head, while leaf lettuces spread out their leaves as they grow.

Leaf lettuce can be harvested just a few leaves at a time, which makes it an excellent choice for beginners and indoor gardens. As soon as the leaves are several inches high, you can remove the outer leaves, and the inner ones will continue to grow. Eventually, the lettuce plant will stop producing new leaves, and it can be removed and another vegetable grown in its place. Leaf lettuce can also be cut all at once if desired.

Head lettuce is harvested as the whole head. While the head is still forming, you can remove some of the outer leaves. Once the head is fully formed, you can cut off the head at the soil surface.

Rinse harvested lettuce in a sink or bowl of cold water. Shake off the water or use a salad spinner to remove most of the water. Then, store the lettuce in the fridge. The sooner you eat it, the better it is! But the cold temperature and some moisture will help lettuce stay crisp for about seven days.