Growing vegetables indoors is a great way to increase the fresh produce you have access to all year. Lettuce, in particular, is one vegetable that can be grown quickly and affordably at home. This article will teach you how to grow lettuce indoors so that it’s always on hand for salads or sandwiches!
Growing your lettuce is an easy way to ensure that fresh produce is always available if you’re tired of buying lettuce every time you want a salad or sandwich. You don’t need to have a sizeable outdoor vegetable garden either, and you can grow inside with a tiny pot.
With food costs soaring (especially fresh produce), growing your own organic lettuce is an easy solution to ensure you have fresh greens in your diet without paying an arm and a leg at the market. Plus, there’s nothing like the taste of fresh produce you grow yourself!
Choose Varieties of Lettuce Plants That will Thrive in Containers
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There are three different types of lettuce you can grow indoors: leaf, head, or romaine. Each has its pros and cons – read on to figure out which one is right for your growing space!
Loose Leaf Lettuce
Leaf lettuces come in many varieties, like green oakleaf, red salad bowl, or green iceberg. Fluffy leaf lettuce is your best bet if you grow lettuce in a hydroponic or aeroponics system. They are more forgiving of lack of nutrients and consistent light exposure, making them easier to grow indoors for beginners. One downside is that they do not last as long as head lettuces, but you can make tasty leafy green salads with these varieties.
Head lettuces are one of the most popular types of lettuce. They are easy to grow inside, but they will only last about one month if you keep them growing indoors, so plan on doing frequent re-plantings with this type. It is worth the effort; a head of lettuce grown indoors taste far superior to lettuce from the store.
Romanesco varieties have some disease resistance but can be more challenging to grow inside.
There are smaller varieties that grow exceptionally well in small containers indoors. We especially love Little Gem. Little gem is a small romaine type that grows well in containers and has very few problems with disease. It’s also delicious and my absolute favorite lettuce to grow inside. One head is perfect for a personal full-size salad.
Butterhead lettuce is Bibb-type lettuce that forms tight a rosette of dark green leaves. We love butterhead lettuce for its tender sweet leaves and ability to tolerate hot weather.
This type of lettuce is very easy to grow indoors and only takes 57 days to mature.
“Buttercrunch” is one of our favorite varieties for wraps or as a low-carb substitute for hamburger buns.
- Learn More: We have a post with our best suggestions of what vegetables grow best indoors and the best vegetables for containers you want to check out.
Choose the Right Size Pot with Adequate Drainage Holes
You can plant your lettuce in different sized pots, so long as your container is at least three inches deep. You do not need very deep containers to grow lettuce, and anything deeper than 3 inches is a waste of space and soil.
The pot should also have drainage holes to ensure excess water can drain away. Excess moisture can cause diseases in your homegrown lettuce.
Use Fresh High-Quality Potting Soil
Use a good quality potting mix. It shouldn’t contain heavy fertilizers because too much nitrogen will cause your lettuce to bolt (go to seed).
The soil should be loose and not compact. You don’t want to pack it down, or you will have a hard time watering the plants
Plant Your Lettuce Seeds On Top of The Soil
Planting your seeds is incredibly easy:
- Pre-moisten your soil before planting your lettuce seeds. It is easier to moisten the soil than adding water once your seeds are planted. Lettuce seeds are incredibly tiny and can easily be moved or displaced by water.
- Plant lettuce seeds on the top of the soil and sprinkle a light dusting of soil over the top. Lettuce seeds require light to germinate, and planting too deep can reduce germination rates.
- Depending on your container’s size, you will only need a few seeds. Plant a few extra to ensure germination but only grow as many that will fit inside the pot. Overseeding will cause overcrowding which can lead to poor growth and poor air circulation.
- You will want to ensure that the area where the seeds are to germinate maintains a consistent temperature between 65-70F.
- In 7-10 days, you should see development of lettuce sprouts begin to show.
- Cover the container with a dome, clear plastic bag, or plastic wrap until the seeds have germinated and lettuce seedlings are at least 1/2 inch tall.
- Place the lettuce seedlings on a bright sunny windowsill or under indoor grow lights.
Water Lightly but Often For Crisp Tasty Lettuce
Lettuce is one of those plants that doesn’t need much water once established. The soil should always be moist but never soggy or wet. Several light waterings will result in healthy crisp lettuce plants.
If your soil is dry, you should water it, but if the leaves start to wilt, wait until they recover before watering again.
Provide at least 6 hours of Sunlight a Day
Lettuce plants need at least six hours of full sun a day. Some varieties are better suited for shade and can tolerate partial shade. The best types for growing indoors without additional artificial light are those that mature quickly and do not produce a long stalk.
Although lettuce requires sunlight, it is essential to watch out for the inside temperature. In mid-summer, a hot south-facing window is not ideal for your indoor lettuce plants.
High temperatures will cause your indoor lettuce to bolt and turn bitter. When the weather warms up, move your lettuce to an East facing windowsill where it can still receive sun but will be kept cooler during the warmest part of the day.
- Related: Lettuce is a vegetable that will tolerate a shady spot. If you have a shady spot in your garden, check out my post on which vegetables grow best in the shade.
Fertilize Every Two weeks for Sweet Lettuce Leaves
Feed your indoor lettuce plants every two weeks with a balanced, water-soluble organic fertilizer, such as a 10-10-10, diluted to half strength.
Fertilizer will keep your lettuce plant healthy and lush and help prevent bitter leaves.
Address Insect Pests As Soon As Possible
Growing lettuce indoors will help prevent insect pests munching on your leaves. Beetles, cabbage loopers, and cutworms are all garden insects that you should not have to deal with indoors.
However, aphids can still be a problem indoors. If you notice tiny holes or lightened patches on your lettuce leaves, turn the leaves over to check for small white-bodied insects.
If you have aphids on your lettuce, the best way to deal with them organically is to rinse the lettuce off under the tap. A quick blast of water will usually suffice.
You can also use an organic insecticidal soap for heavy infestations every 3-5 days for 3 weeks or until the infestation is under control.
Use Preventative Measures Against Diseases
Several diseases can affect lettuce, but most of those diseases are soil-borne or spread by insect pests that you should not have indoors.
With that said, there are several ways to prevent any diseases while growing lettuce indoors.
- Start with fresh potting soil and never use soil from the garden indoors.
- Ensure your container and potting soil are both very well-draining to ensure roots do not become waterlogged.
- Do not overwater.
plant New Seeds in New Soil Every Week or Two
You can plant lettuce indoors every one or two weeks for a continual harvest or fresh lettuce. Staggering the plantings allows for a harvest every few days. Lettuce grows quickly, especially leaf lettuce types. You can expect to start harvesting leaves three weeks after planting.
You can reuse your potting soil at 50%, but you will want to add fresh soil to put back some of the lost nutrients.
Harvest Your Lettuce and Enjoy!
Whether you harvest leaves or sprout heads depends on the variety of lettuce you grow
You should lightly trim leaf lettuce leaves in the early leaf growth stages for tender sweet leaves. Harvesting often will also encourage new growth.
You will want to allow head lettuce to grow to maturity before harvesting. Then, use a sharp, clean knife to harvest a head of lettuce or romaine lettuce to cut the head away from the roots.
Store your fresh lettuce in a bag in the refrigerator for 7-10 days.
Frequently Asked Question about Growing Lettuce Indoors
Here are a few FAQs for planting lettuce indoors:
How long does it take to grow lettuce indoors?
You can expect your first harvest of indoor lettuce about four weeks after planting seeds. Continue to pick the outer leaves, so they do not get bitter or tough. You can pick lettuce anytime, and you do not have to wait until it is fully grown before it is ready to harvest.
Why is my lettuce wilting?
Overwatering is one of the primary causes of wilting. Check your soil. Is it moist or wet? If you think you are overwatering, cut back. Several light waterings are far better for your lettuce plant than sporadic deep waterings.
But it could also be due to a lack of water. Lettuce will wilt in the heat of the mid-day sun, especially if the soil is dry. Check your soil; is it very dry? If the soil is dry, try watering to see if the plant perks back up.
Can you re-grow lettuce indoors in water?
You can grow lettuce in water, but it will not be as nutrient-rich as lettuce grown in fertile soil.
Romaine lettuce is best if you want to try this method.
Add the lettuce base to a glass of water and place it on a sunny window. Be sure to replace the water every few days.
Growing Lettuce Indoors is Easy!
If you’ve been looking for a way to grow your own lettuce and haven’t had much luck with outdoor gardening, the answer may be simple as growing it indoors. Lettuce is one of those vegetables that can produce quite well in many climates – even inside!
In fact, many people grow lettuce year-round and never have to buy it again.
Looking for More Vegetable Growing Inspiration?
Are you interested in growing your own vegetables or fruit indoors, or in containers? I have many articles dedicated to just that subject for you to read:
- How to Grow Green Beans in Containers
- How to Grow Blueberries in Containers: Everything You Should Know!
- Growing Pumpkins in Containers – Yes, you can!
- How to Grow Strawberries in Pots
- How to Grow Kale in Containers
- Perfect Vegetables for Fall Gardening
Editorial Note: This post was originally published on December 30, 2021, and was updated on April 9, 2022