How to Grow Lettuce Indoors: A Complete Guide to Growing Your Own Greens - Backyard Boss
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How to Grow Lettuce Indoors: A Complete Guide to Growing Your Own Greens

Lettuce is the unsung hero of great salads, burgers, and wraps. It can help with weight loss, it fights off inflammation, promotes great and brain health, and aids in digestion. The question is: How do you grow your own lettuce indoors?

You might think this is a difficult process, or maybe you just don’t know how to get started. But as far as

Lettuce Growth Q&A

Can Lettuce be Grown Indoors?

Yes, as long as you provide it with the proper conditions it needs to thrive. Lettuce can be grown indoors if you can provide temperatures between 65 and 70° F.

What is the Best Lettuce to Grow Indoors?

There are many different types of lettuce that you can grow, but for indoor purposes, loose-leaf lettuce is the one you want to go with. Not only is it easy to grow indoors, but it also provides you with a steady supply of lettuce. There are also certain varieties that stay small, making it easier to grow them in containers when you have limited indoor space. If you come across a variety of lettuce with the words “little” or “baby” in its name, that’s the one you want to choose for indoor growth.

growing lettuce indoors in plastic bottle planters

How Long Does Lettuce Take to Grow Indoors?

It really depends on the variety of lettuce that you are trying to grow and if you meet the conditions related to temperature, watering, and fertilizer. Indoor-grown lettuce can take anywhere between 30 to 45 days to be ready for harvest.

Can I Grow Iceberg Lettuce Indoors?

lettuce growing indoors micro greens and mesclunYes, but it can be a bit tricky if you can’t meet all the requirements that the plant requires to thrive. The lettuce will still need to be placed in a spot where it can enjoy at least 12 hours of sunlight every day.

Can You Grow Iceberg Lettuce in Pots?

While it is possible, you need to take into account the fact that iceberg lettuce is planted 5 inches below the surface of the soil and requires at least 10 inches for it to properly grow.

What is the Easiest Lettuce to Grow?

Loose leaf lettuce is the easiest one to grow because it doesn’t have a head (yes, I know how that sounds). While it takes about 45 days for the plant to reach maturity, you can trim the plant in three weeks and start consuming it.

Does Lettuce Need Direct Sunlight?

Yes, it does. Lettuce is a plant that thrives under direct sunlight, so even if you grow it indoors, it is best if you leave it near the window so it can soak up as much sun during the day as possible.

How Many Hours of Sun Does Lettuce Need?

The minimum amount of sun that a lettuce plant needs to grow is 12, but it is best if you aim for 14 to 16 hours of daily sunlight exposure. Alternatively, you can also invest in grow lights in case you are growing the plant indoors and simply don’t have the means to expose it to that many hours of sunlight each day.

Can You Grow Lettuce in Pots?

Yes, you can, provided that you plant the lettuce correctly. In the next section, we are going to tell you just how lettuce can be planted in pots, so if you follow our guidelines, you too can be the proud owner of a thriving lettuce plant.

lettuce seedlings mixed variety in planter

How To Grow Your Own Lettuce Indoors

lettuce seedlings in temporary pots indoors

  • There are different types of lettuces, with some of them being better for indoor growth. Some of the varieties that you can choose include Merlot, Garden Babies, Salad Bowl, Tom Thumb, or Lollo Rosa.
  • Grab an empty pot and fill it with a seed starting soil mix. When you’re picking the pot, take into account the fact that lettuce needs about 4 to 6 inches of space and about 8 inches in depth. Make sure the pot has a drainage hole on the bottom, as the soil of the lettuce needs to be properly drained.
  • If you’re planting seeds, make sure they are about one inch apart from one another. Place them at a depth of 4 to 6 inches into the pot, and make sure that you don’t plant more than 4 seeds per pot. Lettuce tends to occupy a lot of space when it grows.
  • Once the seeds are in the pot, sprinkle some potting soil on top of them.
  • For watering, you can use an empty spray bottle and gently spray the soil. You will need to spray the seeds every day until you notice sprouting. Make sure you poke the soil with your finger about twice per day, and if you notice that the soil is dry, water it again.
  • Make sure that the pots stay at a room temperature of 65 to 70° F. Yes, you will have to use a heater or an air conditioner if temperatures are below/above the recommended interval.
  • Lettuce needs sunlight to grow, so it’s best if you leave the pots next to a window throughout the day. Alternatively, you should invest in a grow light to make sure that they get about 14 to 16 hours of light every day.
  • If you notice the leaves wilting, don’t be afraid to spray them with more water.
  • Make sure that you fertilize the lettuce 3 weeks after planting. Choose a fertilizer that’s rich in nitrogen, preferably a liquid one.
  • Lettuce that’s grown indoors is usually ready for harvest in about 30 to 45 days after planting. When grown indoors, the plant usually reaches about 4 inches in height when it’s ready for harvest.
  • If you simply cut the outer leaves of the lettuce and leave the middle ones just as they are, you can get a steady supply of lettuce. You can cut the outer leaves with scissors and store them up to 10 days in the fridge (the freshness of the lettuce will depend on the variety grown).

BONUS: How to Grow Your Own Lettuce Outdoors

  • Being a cool-season crop, lettuce can be grown and spring and fall, with seedlings even being able to tolerate a little bit of frost. You can start sowing when the soil temperature is above 40° F.
  • You will notice the seeds starting to germinate in about 7 to 10 days, at temperatures between 55 to 65°F. Since it is a fast-growing plant, it’s best if you plant small amounts at a time.
  • You can either directly sow the plants into the ground or you can plant them inside about 4 to 6 weeks before frost is gone to get a head start on your crops.
  • When you start planting outside, make sure the seeds are planted ¼ – ½ inches deep into the ground. You will also have to thin them when the plants reach 3 or 4 true leaves. When you want to transplant them into the soil, they should have a well-developed root system and 4 to 6 mature leaves.
  • You should have about 12 to 15 inches of space between each planted row.
  • Once you’ve seeded the lettuce, make sure to cover it with ¼ to ½ inch of soil.
  • When you transplant, make sure to water the plants
  • After transplant, you will have to fertilize the seeds when 3 weeks have passed. You will need soil that’s rich in organic materials, with a generous amount of nitrogen and comport. Slow-release fertilizer and organic alfalfa meal are your best choices.
  • The soil needs to be well-drained but has to remain moist at all times.
  • The good part about growing lettuce is that the leaves will tell you when they need water. If you notice the leaves start wilting, you can sprinkle them with water.
  • The right time to harvest the lettuce is before it reaches full maturity, but the plant is full-grown. That’s when the leaves are most tasty. It is also better if you harvest the lettuce in the morning, before it’s exposed to powerful sunlight.

mixed lettuce leaves in strainer bowl in sink

Bottom Line

Did you know that lettuce belongs to the daisy family? While you can’t eat daisies, you can surely include lettuce in your diet to enjoy all the nutritional benefits that this plant has to offer. What’s more, growing your own lettuce is quite easy, regardless of whether you plan on doing it indoors or outside.