I am an amateur gardener who I loves to grow food. I also love the idea of eating fresh organic produce. Extreme weather during the year can make outdoor gardening impossible leading to my attempts to grow lettuce indoors. This article describes the process I used to plant my indoor lettuce garden.
To get started I read the book, “Indoor Salad: How to grow vegetables indoors” by Gnger Booth. Booth describes her methods and what has worked for her in detail. She also provides recommendations on what kinds of lighting to use, growing methods and mediums, and seed varieties.
Why Grow an Indoor Lettuce Garden
One of the main reasons for growing food indoors is due to extreme weather. Lettuce just does not do well in 100+ degree heat. As the weather heats up, mature lettuce will bolt and go to seed. In cooler climates, the growing season generally ends at the first freeze. There are ways to extend the season with cold frames and greenhouses, but a year round indoor lettuce garden can easily solve the problem.
One year I did produce a prolific Black Seed Lettuce garden. The lettuce was delicious; however, it took a lot if effort and time to wash off tiny bugs who also liked my lettuce. Many pests that trouble outdoor gardens can be mostly or even completely avoided indoors.
When you grow your own lettuce, you know exactly what you put into it. You can completely avoid the use of pesticides and have pure organic produce.
Another reason to try your hand at indoor gardening is freshness. Lettuce bought at a grocery story can vary in quality (depending on how old it is). If you live far from the farms, your lettuce will taste worse. If you live closer to farms, your lettuce may be satisfactory but only last a week or two depending on how you store it. Freshly cut lettuce will likely taste better and have more nutrients than old lettuce. If you grow your own indoors, you can cut your lettuce as you make your lunch, dinner, or anytime salad. You really cannot get fresher than harvesting lettuce right before you eat your salad.
How to Grow Your Own Indoor Lettuce Garden
Shop light fixture
Buy a T8 fluorescent Shop light fixture. I bought this one from Amazon. It is 4 feet long and fits across my 2 shelving units. The one I bought comes with S-hooks and a chain for hanging the fixture.
Two T8 fluorescent light tubes to fit in your fixture. I bought this 2-pack from Amazon and have had great results.
Shelf to hold up the lighting and plants
The shelves I use for indoor gardening I bought from IKEA about 5-8 years ago. They were less than $20 each. I don’t think IKEA still sells these. You can really use anything that is sturdy enough to hold up your pots/planters and that can be used to support your lights. You will need a way to hang your lights from the shelf. My shelves are made of wire mesh, so I can easily attach my hanging chains to the shelves. I open one end of the chain with pliers, hook it on where I want it, and then close the chain with the pliers. If you are using plastic shelves (plastic garage shelves wood also work), just drill a hole large enough to slide your chain through. Then, secure it with a nail, pin, or other object that can slide through the chain to secure it.
I bought my self-watering container from Walmart. As you can see, mine is in the shape of a window box. I chose this one as it fits well on my shelf.
Miracle Grow potting mix (get the general one)
Ginger Booth recommends regular Miracle Grow Potting mix. She says to avoid the moisture control version and explains her rationale in her book. I just went with her recommendation.
Seeds (I used salad bowl)
You may be able to find the “Salad Bowl” variety of lettuce seeds locally, but they are also available on Amazon.
Put the potting mix in your planter. Add water to moisten the soil. Plant your seeds in your chosen container. If you plant them closer together, you may need to thin out the seedlings to avoid overcrowding. I have about 6 lettuce heads growing in my 2-foot long planter. Spacing does not need to match the recommendations on the seed packet as the goal is not to grow a full head of lettuce to maturity, but for continual harvest of outer leaves. Spray the top of the soil so it remains moist until the seedlings emerge. Then water from the bottom of your self-watering planter as needed.
I did not keep careful records of how long my process took, but it was 3 weeks from when my first grow lights arrived from Amazon to my first harvest. So, I would expect you could start harvesting lettuce leaves in 2-3 weeks from planting. To harvest, take cut off outer leaves with a pair of clean kitchen shears. Be sure to leave inner immature leaves as they will continue to grow.
Rinse and dry the lettuce if desired. Then prepare and enjoy your fresh home grown organic salad.
How to Maintain Your Indoor Lettuce Garden
Continue to water as needed. Also harvest outer leaves regularly to keep the heads at a reasonable size for your planter. If needed, you can also harvest a whole head to improve spacing in your planter.
Although I am not there yet, I may need to add fertilizer to my planter after 6 months. My potting mix says it already contains enough fertilizer for 6 months, so if I am still harvesting then, I will add fertilizer. If not, I will just start over with new potting mix.
Conclusion on Your Own Indoor Lettuce Garden
My indoor lettuce garget is a success! Since this is my first time trying to grow lettuce indoors, I am not sure how long I will be able to harvest from these particular heads. I have been cutting leaves for salad several times per week. Most of my children are actually eating it as well. They like the test of freshly cut lettuce. I wish I had planted a second box with the same lettuce so I could harvest daily.
Keep the soil moist until seeds sprout. Afterwards, you can let the soil dry a little between watering. I started with keeping mine too wet and then had some green growth of something on top of the soil. I cut back on watering and my lettuce remained healthy and the green growth subsided.
Science Extension Activities to use with an indoor lettuce garden
One of my children is really interested in botany, and growing lettuce is a great hands-on way to study the development of a plant. Here are some science activities to try:
- Study the parts of a seed and seedling and label them as the baby plants emerge
- Document the plant’s growth over a week or two. Measure the seeding or leaves, draw pictures of changes, and graph results. Compare the growth of different types of seeds.