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How to Care for Growing Lettuce

A collage of growing lettuce until harvest.

You can care for growing lettuce indoors and outdoors quite easily as a home gardener. That’s because lettuce is a simple vegetable plant to germinate and produce. As a way of saving money and reducing the use of plastic, our household uses an AeroGarden to grow plants indoors. Learn about how to successfully care for growing lettuce and about other tips in this guide on planting and tending lettuces.

How to Get Started With Growing Lettuce

Long before you can put your fully grown and harvested head of lettuce on the shelf in the fridge, you have to grow the lettuce. As a home gardener, having lettuce ready to eat from seed takes about 90 days, and most people go that route to save money. I pay 50 cents a pack for lettuce seeds of all varieties at the local market and the packs have approximately 100 seeds most of the time. 

Pineapple and lettuce on the fridge.

Lettuce plantings can also be purchased and used to grow large quantities for outdoor gardens. This speeds up time and eliminates risks associated with germinating seeds for lettuce plants. However, it costs more money, about $6 to $9 per plant, to start from plantings when growing lettuce. 

Growing Lettuce From Seed

To grow lettuce from seed is very simple. You need soil or a soil medium and some water, as well as sunlight. The seeds are sprinkled directly onto the soil and covered lightly. If planted in rows, I dig a thin trench all the way down the row and sprinkle seeds every inch or so. 

A man planting seeds on the seed box.

From here, allow the seeds to grow and come up into plantings about 4 inches tall. This is when I remove plants that are weak or yellow in favor of those that are taller and stronger at the stem. The pruning out also allows those stronger plants to have the necessary space to take hold of their roots. The plants develop more fully and this increases yield. As for the smaller, weaker plants, those get tossed in the compost or behind me on a grassy knoll.

How Long Does it Take for Lettuce to Grow?

According to the garden watering experts, Gilmour, “Lettuce grows fairly quickly. Leaf varieties reach maturity in 30 days but can be harvested as soon as they reach the desired size. Other types of lettuce require 6 to 8 weeks to reach full harvest size.” This makes it super fast to get lettuce from the seed packet to the lunch table, and a reasonable vegetable for beginner gardeners.

How Do I Keep Lettuce Alive in My Garden

The best way to keep lettuce alive in any garden is by reducing the sun exposure and temperature. Any time the temperature is over 70 degrees, the lettuce is at risk of bolting. Just like cilantro, lettuce will bolt when the temperature is too hot and leave you with nothing worth eating. 

A large lettuce plantation ready for harvest.

Tight-headed types of lettuces, such as crisphead, are particularly prone to shooting up with a tall stem when they are supposed to create a compact ball shape. This is problematic, particularly for farmers, but according to Love to Know, you also end up with bitter tasting inedible leaves, which is pointless to grow. Water and the right nutrients brought in through fertilizer is also important for growing well-cared for lettuce.

Does Growing Lettuce Need Full Sun?

Not really! You can grow lettuce in full sun, but shade in some parts of the day is key to keeping lettuce cool, no pun intended, as a cucumber. Otherwise, the lettuce grows too quickly and does not form the sweet flavored fibrous material we love in salads and wraps. It’s called iceberg lettuce for a reason–you want there to be chill involved with growing all types of lettuce.

Will Lettuce Grow Back After Cutting?

According to Tiny Garden Habit, “Lettuce regrows once its leaves have been cut or picked off the main stem. As long as the root is intact in the ground and there are at least 1-2 inches of stem and leaves at the base, lettuce will shoot new growth in as little as a week.”

A woman with pink hair holding a basket of seedlings.

Do I Prune My Lettuce Plants?

You can prune lettuce plants by cutting down the entire plant and harvesting it, and allowing new leaves to sprout up. However, pruning is not needed.

Do I Transplant My Lettuce?

Lettuce plants that are less than six inches tall can be transplanted to a deeper soil medium. Dig a hole for the length of the root system and loosely shift soil around the roots. Once transplanted to an outdoor garden bed, raised garden plot, or indoor container, the surrounding soil should be watered with cool water until damp. 

What Helps Lettuce to Grow

The right light, temperature, water level, and fertilizers will help lettuce plants grow and thrive. 

A lettuce plant hanging on the wall.

However, the amounts vary depending on the planting location/environment, the type of lettuce, and the time of year. If I am planting lettuce in the spring, which is the typical season, I use the light from the window or the shaded area of the lot to plant lettuce. This allows me to reduce direct sunlight. I also recommend adding a shade cloth over the top of lettuce plants if you have to grow them in the sun or if the weather forecast is particularly sunny or hot. 

Watering is important and so is fertilizing to feed lettuce plants. These plants only grow for one month before harvest in most instances. Therefore, you typically do not need to add fertilizer until after the first harvest. This will boost production for the second yield and increase overall production and nutritional value.

How to Fertilize Lettuce

Choosing between organic and conventional plant food is the first question I ask when planting any plants. For lettuce plants, I prefer to use organic plant food since the plant is eaten straight from the stem without cooking it. Crystalized fertilizer that is water soluble is the recommended method for lettuce. Feed the lettuce this type of fertilizer when lettuce plants are four inches tall.

Which Types of Lettuce are Easiest to Grow?

The easiest types of lettuce to grow are those with a loose leaf and all green. Red leaf and frilly lettuces are more difficult to grow compared to loose leaf romaine. However, compact types of lettuces including iceberg, crisphead, and butterhead are harder to grow. This is because the shape can be lost due to bolting caused by heat.  

How to Grow Romaine Lettuce

Romaine lettuce is a slow bolting type of green that does not require a ball shape to come to harvest. Instead, the lettuce is grown into long flat leaves, which is easier to tend to and reduces the risk of insects or mold within the lettuce. This makes it simple to grow romaine lettuce. Let the leaves grow until harvestable length, and cut down in one bunch. Allow the plant to regrow at least one more harvest. 

Which are the Hardest Lettuces to Grow?

Surprisingly, one of the hardest lettuces to grow is iceberg lettuce. Even though this is the easiest to find–you can get iceberg on tacos and burgers at every fast food restaurant–it is the most difficult in the field. That is because of the round, tight shape. Also, iceberg, as the name suggests, is best when it grows chilled. The leaves are broken down somewhat by the cold temperatures that freeze the plant’s cells. 

Red lettuce grown in the labs.

As a result, the plant is easier to digest for the end consumer. The lettuce leaves also taste sweeter due to the sugars processed as the lettuce plant freezes and melts in cool growing climates. Spring and summer are hot around the world, and this is why it is hard to grow iceberg lettuce and other lettuces that like to keep it cool or they bolt!

Is Hydroponics Good for Growing Lettuce Indoors?

Hydroponics is the use of water to grow lettuce, which is beneficial for indoor gardeners. I love this method as it reduces the use of a lot of soil. Some soil is needed for the seed to germinate, but for the most part, the water does all the work in feeding the lettuce. Since lettuce is mostly made from water, hydroponics makes sense and works wonderfully.

How to Grow Lettuce in Water

I suggest, if you want to go with hydroponics, you purchase an AeroGarden machine or some similar system. This is the easiest way to manage all the aspects of growing lettuce. The lighting is on a timer and the watering reservoir is on a pump for oxygenation purposes.

Can I Use an AeroGarden to Grow Lettuce In My Home?

The AeroGarden planting system is a great way to grow lettuce in your house. I live in an apartment and in the farthest room from everyone is the bathroom–where I grow our lettuce. The AeroGarden works very well there, thanks partly due to the humidity.

It is also nice to have the bright light of the AeroGarden, which comes on via a timer, to use to brighten up that dark room. When I used it in the kitchen window, the AeroGarden became a beacon–to would-be criminals. I would not advise using this gardening system to grow lettuce in a window where people could break in because of the super bright lights.

AeroGarden Harvest Elite - Indoor Garden with LED Grow Light, White Stainless

I am not a sponsor or seller for AeroGarden, but for gardening and growing lettuce indoors, the AeroGarden is ideal. This is a hydroponic system that has growing lights on a timer and the water pumps and requests fertilization automatically. You also see great gains in gardening.

“AeroGarden plants last for 3 months on average. Flowers and herbs go a little longer, and lettuce lasts a little less. Fruiting vegetables, such as tomatoes and peppers, can live up to 9 months long. Good care and a fresh hydroponic solution will help the plants live a long time,” according to these AeroGarden owners.