Grow Your Own Lettuce from Seed

The first time I ever grew lettuce, I let my toddler scatter Rocky Top Mix Salad Blend seeds all over our raised beds. We kept the beds well watered, and in just a couple weeks, there was more lettuce growing than we could eat, even if we enjoyed daily salads for lunch.

And it was like that for months. We marveled at how much success we were suddenly having in the garden after struggling with fruiting plants for years, and it wasn't long before we became gourmet lettuce snobs.

You might experience this too. It's hard to go back to grocery store leaves when you've tasted the most delicious homegrown ones.

Lettuce is super easy to grow from seed, which is great for those of us who love our spring mix because lettuce plants don't transplant very well. If you see cute little lettuce plant babies for sale at the store, avoid the temptation to buy them. Get yourself a little package of lettuce seeds instead, for the same price as one lettuce starter plant. You'll be able to grow way more plants (and healthier plants, at that) from seed in no time at all.

Planting lettuce seeds involves little more than spacing the seeds out and then stepping back to watch them grow.

The Best Time to Grow Lettuce from Seed

Tried growing lettuce before but didn't have a whole lot of success? It might have been an issue of temperature. Lettuce plants like cool weather. Their ideal temps are between 55°F and 75°F.

If you plant lettuce when it's too cold outside, your seeds will likely take longer to sprout and grow. But if you plant lettuce when it's too warm outside, your seeds may still sprout, but you're not likely to enjoy the plants for very long. They'll feel stressed by the warm temps and do something called bolting, or focusing on seed production.

For most of us, lettuce grows best during spring and fall. You can begin sowing lettuce seeds a little before your last frost of the spring, basically as soon as the soil is workable, and continue sowing until the temps grow too warm. In the fall, you can start anew a couple weeks before your first frost date. I used to plant lettuce in September when I lived in Chicago. I covered them with frost cloth in October and November and enjoyed a lot of production.

Those of you who live in a warmer climate, like my friends in Houston, would actually do best growing lettuce throughout your winter months.

Before you sow lettuce seeds, check your average high temperatures for the next couple of months. You need at least 45 days of nice, cool temps (below 75°F) ahead to grow lettuce.

The Best Plant Spacing for Lettuce

How much you space out your lettuce seeds will depend on what type of lettuce you're growing and how often you intend to harvest the leaves. The closer you plant your lettuces, the more often you need to harvest.

Spacing for Head Lettuces

Head lettuces like romaine and iceberg are overall larger lettuce plants, so they need a little more space if you'd like for them to develop a full head. These will need to be spaced about 6 to 9 inches apart. Check the expected width of each plant when mature, and make sure to give that much room between each plant.

Spacing for Looseleaf Lettuces

If you're growing smaller plants like spring mix or Black Seeded Simpson, you can sow your seeds in rows and give each plant space to grow to its full potential, or you can scatter your seeds and let plants grow close together. You should space seeds about 5 to 6 inches apart if you plan to wait to harvest until the plants are full size. Otherwise, you can space plants about 3 to 4 inches apart. This spacing assumes you'll be harvesting outer leaves often to keep the plants small. They don't really need a lot of room in order to produce leaves, but you want to avoid issues with mildew and mold.

All right, let's look at the steps to sow lettuce seeds.

Prepare the Soil

Whether you're growing in a container or raised bed, it's a good idea to do a little soil prep before sowing lettuce seeds.

First, use your hands or a little hand rake to loosen up the top couple inches of soil in the planting area. Lettuce seedlings like having lots of little air pockets that their roots can spread into. Remove large pieces of debris and break up clumps of dirt.

Second, add some organic matter like compost (I love mushroom compost) or earthworm castings to the soil surface. Lettuce plants love growing in nutrient-rich soil, and this will give them enough nutrition to power their entire growth. (You shouldn't need to apply additional fertilizer or anything.)

Then, use your hand or something flat to level the soil surface. You don't want any dips or mounds that could cause your lettuce seeds to slip and slide when there's rain.

Finally, moisten the soil a bit. I like my lettuce seeds to encounter wet soil from the very beginning.

Space Out Lettuce Seeds

Sowing lettuce seeds is a bit different from something like beans or squash. You really don't need to dig holes or bury seeds at all because you're dealing with very tiny seeds. So tiny, in fact, that I recommend taking off your gardening gloves before planting them. It's much easier to handle them with bare hands.

If you're hoping to grow large leaves or full heads of lettuce, then your best option is to take some time when you're planting to space out your lettuce seeds and plant in staggered rows. I highly recommend getting a seed spacing ruler if you don't have one. These rulers have a small hole at each inch mark that you can deposit a seed (or two or three) into.

If you don't have a seed spacing ruler, you can use a measuring tape or the markings on a dibber to help you space your seeds out. One advantage to using rulers and measuring tapes is having a nice, straight planting line.

Pour your seeds into the palm of one hand and use the opposite thumb and pointer finger to pick up one seed at a time. Drop a seed into the holes of the seed spacing ruler or next to the appropriate measurement.

Leave all the seeds uncovered until you're done.

You can either plant all your seeds now or plant successively every couple of weeks if you want to spread out your harvests. To succession sow, skip every other row and then return in a week or two to sow more seeds between your planting lines.

Pat your seeds down gently to make sure they have good soil contact once they're sown. You can use the edge of the planting ruler or just your hand to press them into the soil.

Take some extra compost or your soil blend and sprinkle it over the planting area like pixie dust. You just need a little bit of coverage. If you can still see some seeds on the surface afterward, it's okay. Avoid burying these guys too deep because then they'll struggle to reach the surface. Even if they do make it to the top, they'll be too exhausted to actually grow. 

If you plan to plant other things in the same bed, make sure to mark where you've sown your seeds so you don't double-plant.

Water Lettuce Seeds In

Water your seeds in using the gentlest setting on your hose. Mimic a soft rainfall, not Niagara Falls, okay? You don't want to wash away all those tiny seeds you just placed.

Lettuce seeds must stay moist to sprout and grow. You'll need to check the soil moisture daily so that it never dries out. Even once your seedlings have popped up from the ground, you still want to keep the soil consistently moist if you'd like to have the tastiest leaves possible. Be prepared to water by hand regularly or set up a drip irrigation system on a timer. The smaller the container you're growing in, the more frequently you'll need to water since it'll dry out faster.

Other than regular watering, your lettuce plants require very little maintenance once they start growing.

Protect Your Lettuce Plants from Pests

If you're worried about birds pecking at your lettuce seeds or garden pests attacking your tender leaves, take the extra step of covering your planting area with inexpensive tulle fabric or garden mesh. The best time to do this is immediately after planting.

Here's how that works: You pick a porous cloth that lets air, water, and sunlight in, but keeps pests out. You'll leave this mesh on from the day you plant your lettuce onward, so pests never have the opportunity to enter the space. That simple physical barrier is enough to protect your plants from smaller pests like aphids, slugs, and caterpillars, and even larger pests like bunnies and squirrels.

If you're growing lettuce in a raised bed, grab some garden hoops and landscape pins to go with your tulle or garden mesh. You'll install the hoops every couple of feet so that they span the entire bed. Drape the mesh over the hoops to keep your plants from getting smooshed. The landscape pins will go around the edges of the planting space to hold the fabric in place.

To harvest, just remove some pins and lift up the fabric. Replace once you're done.

You'll be amazed how effective this form of pest control can be—no chemical pesticides required! You'll also help to lock in moisture underneath the cloth and give your plants some extra protection from strong winds and other harsh weather conditions.

How to Scatter Lettuce Seeds

Now, wait a minute, Nicole, some of you might be thinking. I thought you said we could just scatter your seeds.

I did, and you can absolutely sprinkle your seeds over the soil with all the gusto of a toddler. If you plant this way, the plants will, of course, end up growing very close together. The benefit of this is you can grow lots of plants in a small space, and the plants will shade the soil, which helps to retain moisture (and lettuce plants like moisture). The downside is that if you don't harvest frequently, your plants might not have enough access to air and sunlight.

To scatter seeds, take some seeds in your hand and sprinkle them over the soil like fairy dust. You could also pour some seeds into a clean spice shaker and use the little holes in the lid to help you disperse the seeds. A well-cleaned condiment bottle (the kind with a narrow tip) can be similarly helpful since the opening is small enough to allow only a few seeds to escape at a time. Another trick I've learned is to mix the lettuce seeds with coarse sand. This allows you to better see where you've scattered seeds and where you have not.

Your goal is fairly even distribution across the planting area. Use a hand rake to spread out seeds if you end up with clusters. Then, sprinkle some soil over the seeds and water them in well.

How to Thin Lettuce Seedlings

If several little lettuce plants pop up way too close together, you can thin them to give the remaining plants more room to grow. The best time to thin is about two weeks after sowing lettuce seeds. Just come in with a clean pair of scissors and snip the extra lettuce plants at their base, right at the soil level. Leave the strongest-looking plants to keep growing. Toss the little plants you thinned into your next salad.

Where should I buy lettuce seeds?

Some of my favorite seed companies to buy lettuce seeds from are Botanical Interests, High Mowing Seeds, Southern Exposure Seed Exchange (great for warmer climates), Johnny's Selected Seeds, and Baker Creek.

Try to buy organic, non-GMO seeds. If you'd like to grow something like romaine in a container garden, look for seed packages that say things like "baby greens” or “container variety” so you know the plants will do well being grown in tight quarters.

Here's another thing to keep in mind: Red lettuce varieties tend to tolerate heat better, but they're also more difficult to germinate and grow.

What are pelleted lettuce seeds?

You may have noticed that some seeds in my pictures are small and grayish tan (kind of like teeny tiny footballs), while others are a little larger, rounder, and white. These white seeds are pelleted seeds. That just means the seed company has give them a special coating to make them larger and easier to handle.

Buying pelleted seeds is a great option for those of you with arthritis in your hands or poor vision. The downside is that they have a shorter lifespan than regular seeds. You'll want to plant pelleted seeds within a year.

How much sunlight do lettuce plants need?

Your plants will need at least 4 hours of sunlight per day to produce leaves. Sunlight through a window is a little bit different from outdoor sun, so try to give your plants a little more if you're growing lettuce indoors. Put them right next to the window, and rotate your container every time you water.

Can I grow lettuce over winter?

Most lettuce varieties can be grown under cover throughout a mild winter like what I have here in Nashville. If your climate is warmer than Nashville's, you can grow lettuce all winter long without protection.

For those of you in a colder climate, you can still grow lettuce during the winter; you'll just need a cold frame, a polytunnel, or a greenhouse.

How much can I harvest from one lettuce plant?

You can take a couple leaves from a single lettuce plant every week once it's been in the garden about 30 to 45 days. That's obviously not a lot at the time, but it really adds up over the weeks. If you have many lettuce plants growing, you can rotate which plants you harvest from so that you can cut fresh leaves daily.

With this in mind, I would say you should expect to harvest a salad box's worth of leaves from each package of lettuce seeds at least 50 times. That's $250 of lettuce (if we assume each salad box from the store is $5) for the price of a $4 seed packet!

When can I harvest my first lettuce leaves?

Soon! That's because leaves are the first thing a plant produces. You should be able to take your first harvest in 30 days, as soon as the leaves are a couple inches long.

Lettuce plants are cut-and-come-again, so you can cut a couple leaves from the outside of the plant, leave the plant alone for a week, and then return to harvest some more. I recommend harvesting some of the outer leaves from all of your lettuce plants, even those you'd like to form a full head. It helps control pests and ensures every plant has some airflow around it.

Time to Sow Some Lettuce Seeds!

Growing your own lettuce is one of the easiest ways to get started gardening. Once you've sown those seeds, all you have to do is keep them moist, and soon you'll be harvesting more lettuce leaves than you can eat! There are about to be so many delicious and organic salads in your future!

Honestly, it was harvesting my own lettuce leaves for weeks on end that inspired me to teach others about gardening, especially when I realized all my friends were still buying store-bought lettuce even during prime salad-growing season.

Thanks for being here and helping to make gardening ordinary again!