We all know that freshly picked vegetables are chock-full of essential vitamins and minerals; not to mention yummy! But what about the winter months? Simple — just make your own indoor lettuce garden!
In this article, we’ll teach you how to grow lettuce indoors using either soil or hydroponics. We’ll also provide useful tips along the way to help your plants thrive in their new home.
But that’s just the tip of the iceberg. So let’s get started!
Indoors vs. Outdoors: Which Is Better for Lettuce?
Believe it or not, most lettuce plants prefer the stable conditions of your home in place of your garden. And under the right conditions — near a window, under a grow light, with optimal temperature (15°C to 18°C or 60°F to 70°F) — they will even grow year-round!
Moreover, your home will keep them safe from any pests and diseases that often plague outdoor plants, such as cabbage worms, aphids, blights, etc. Plus, lettuce is so durable that you can grow it in space. So even if you’re a Martian, indoor lettuce is the way to go!
Is Lettuce Easy to Grow Indoors?
You bet! Lettuce is one of the easiest and most popular vegetables to grow indoors, and for good reason too! Namely, it doesn’t require any special care to grow and flourish; it’s fairly low maintenance, which is neat!
All you need is a sunny spot in your home, some soil, and some water; that’s it! Better yet, you can use a hydroponic system if you can afford it; lettuce plants have been known to thrive in those.
That said, there are a few things that you need to be aware of to get the best possible results:
What You Need for Growing Lettuce Indoors?
These types of plants prefer temperate weather conditions with lots of sunlight and moisture. Provide plenty of those and they’ll surely flourish.
However, there’s more to it than that if you want prize-winning lettuce. Here’s what you need to pay special attention to:
Choose the Right Lettuce Variety
Not every type of lettuce plant is suited for indoor growing. For the best results, choose lettuce varieties that are compact and don’t require too much space. That way, you’ll be able to grow more of it without any additional work on your part.
A few great options include butterhead lettuce, romaine lettuce, and loose-leaf lettuce varieties, like Baby Oakleaf and Tom Thumb.
What Is the Easiest Lettuce to Grow?
Some lettuce varieties grow faster than others. So, if you’re impatient like us, you’ll opt for Salad Bowl, Garden Babies, Merlot, and Baby Oakleaf varieties.
Find a Suitable Container
Whether you want to grow romaine lettuce indoors as we’ve suggested or you opted for another variety, you’ll still need a container that’s at least 6 inches deep; and lots of them. After all, you’ll need more than one plant to keep your portable blender busy for your daily health routine to work.
In soil, you want to plant lettuce seeds 4–12 inches apart with 12−18-inch rows. Hence, your indoor container should be roughly the same size (about 1 ft²). To be more precise, leaf varieties should be at least 4 inches apart, and head lettuces — 10.
Planting romaine lettuce, on the other hand, requires seedlings to be at least 6 to 8 inches apart. So you can get away with smaller-sized containers.
Note that lettuce plants are made predominantly of water (95%), and as such, require a consistent supply of moisture, but cannot tolerate wet roots. Therefore, make sure that your containers have drainage holes to prevent roots from rotting.
Pick a Potting Mix
Both pots and hydroponics can make good use of a quality fertilizer or growth-boosting mix. Most herbal stores even have a seed starting mix or two on offer. Use these and you’ll get sprouts growing out of your lettuce seeds in no time!
Get the Lighting Just Right
Once the germination process is complete, your lettuce seeds will want plenty of light; each plant needs about 12 hours of sunlight per day. Therefore, place your container near a windowsill or similar spot that gets plenty of sunlight. Otherwise, use LED grow lights.
And if you’re wondering:
Does a Lettuce Plant Need Full Sun?
Yes, lettuce plants need plenty of sunlight to grow — hence why we recommend using some quality LED grow lights; especially during colder months (spring, winter, and fall).
To do so, place the lights about 6 inches above your plants; any closer than that, and you risk harming your plants. Also, make sure you keep them on for around 14 to 16 hours each day.
Last but not least, be careful not to scorch your plants during the hot summer days. The intense heat can dry up your plants and make them wither away. So make sure you place them in a partially shaded spot.
Temperatures to Grow Lettuce Indoors Year Round
The key to indoor lettuce growing is to keep a consistent room temperature. As previously mentioned, lettuce grows best in milder weather (between 15°C to 18°C or 60°F to 70°F).
Note that if it gets too hot, your lettuce will start to bolt, producing seeds and becoming bitter and inedible.
To prevent that, you need to do the following:
- Use a standard indoor thermometer. Place it in the room where you’re growing lettuce, and check it regularly to ensure optimal temperature.
- Adjust your heating or cooling system to maintain ideal temperature conditions.
- Use grow lights. Most of these come with a built-in thermometer, allowing for easier temperature monitoring in your growing space.
Water Them Regularly
Lettuce thrives on moisture. So water early — and water often!
Make a habit of checking the soil each day. If it feels dry, shower your plants with some love (read: water). Alternatively, you can grow your lettuce indoors in water hydroponics.
Another thing you need to keep an eye out for is — humidity; the more, the better! Conversely, if the room gets too dry, the plants start to wither away.
So, to prevent your lettuce plants from dying a slow and agonizing death, do the following:
- Use a humidifier. Place it in your growing room and turn it on whenever the air feels dry.
- Mist your plants regularly with a spray bottle to keep the air nice and moist.
- Group your plants. When plants are close together, they release water vapor, which increases air humidity; just make sure you leave plenty of space for your plants to grow.
Some Bonus Tips for Growing Lettuce at Home
Here are a few extra tips to make sure your plants get the love and attention they need:
- Avoid letting your plants get too big. Once things get too overcrowded, your lettuce plants will be more likely to bolt. Solution: harvest your plants every once in a while!
- “Leaf me alone!” Keep your growing media out of reach of mischievous, salad-loving pets (even though pet shaming videos are kind of cute, we won’t lie).
- Lettuce is ripe for harvest when the leaves are crisp and green. Make sure you cut the leaves with a high-quality kitchen knife to avoid damaging the stem.
How Long Does It Take to Grow Lettuce Indoors?
It depends on a variety of factors. Here’s to name but a few:
- Lettuce varieties. Not all lettuce are created equal; buttercrunch and deer tongue lettuce plants mature much faster than icebergs, for instance.
- Soil lettuce seeds take about a week to grow into full seedlings. And an additional 30–40 days for the leaves to ripen.
- Hydroponic lettuce takes 30% to 50% less time to grow than soil lettuce; varieties like buttercrunch and romaine lettuce reach harvestable size in a relatively short time span — just three weeks! Icebergs, on the other hand, can take up to eight weeks to fully grow.
How to Grow Lettuce in Pots?
The process is fairly simple if you just do the following:
- First, make sure the pot is clean. Next, fill it with fresh water and add some liquid fertilizer. After that, soak the seeds for 12 to 24 hours.
- Place your lettuce seeds in a container with high-quality potting soil (only the best for my greenery). And remember to poke a few holes at the bottom for drainage.
- Place the container in a well-sunlit area and make sure the water level remains consistent.
- When the lettuce is about 4 inches tall, you can start harvesting! Simply remove some of the outer leaves and let the rest of the plant grow back.
How to Grow Your Lettuce Indoors Hydroponically
Lettuce is one of many salad greens that do well in a hydroponic system. Not only is it faster, but it also takes far less space than soil-grown plants! As a result, you can almost double the yield in just half the time!
Here’s how to do it step-by-step:
1. Set Up Your Hydroponics
Depending on your specific needs, there are different types of hydroponic systems to choose from. Namely, wick, drip, ebb and flow, water culture, N.F.T. (Nutrient Film Technology), and aeroponic systems. Pick one and be sure to read the manual.
2. Plant the Seeds in Plug Trays
How to grow lettuce from seed indoors? Simple, use plug trays!
Just remember to use a soilless seed starting mix instead of the regular (soil) one.
Plant lettuce seeds ¼ of an inch deep in the media, and keep them moist until they germinate; place no more than 2–3 per plug tray.
3. Choose a Spot With Plenty of Sunlight
For maximum gains, grow lettuce indoors with a grow light. Namely, lettuce plants need about 14–16 hours of light per day; you can’t control the wind, but you can adjust your sails, or in this case — light!
4. Thin the Seedlings Out
Once your lettuce plants have germinated and are about 2 inches tall, you’ll need to thin them out to facilitate their growth. You can either transplant the seedlings into individual pots or thin them out so only the strongest plants remain; the choice is yours.
5. Transfer the Seedlings to the Hydroponics
Place the seedlings into the hydroponic panel and space the pots out accordingly.
Don’t forget to leave a one-inch gap between the panel and the water below. This will provide the roots with some much-needed breathing room. After that, just add a ready-mix solution to grow your lettuce indoors hydroponically, and — voilà! We’re all done!
6. Harvest When Ready
Once your lettuce plants are about 6 inches tall, you can start harvesting the outer leaves. The best part, you can harvest them to your heart’s content, and they’ll still grow back! Even so, be patient and let the plants recover for at least a month before making another Caesar salad.
If you’ve decided to grow butter lettuce indoors, you can expect to harvest the leaves within 45 days. Conversely, if you opted for romaine lettuce, you’ll have to wait between 60 to 80 days.
Growing your own salad greens is not only healthy, but it’s also an easy way to save money (apart from the environment, of course). So, if you’re craving some delicious salads that you can enjoy all year round, look no further than lettuce!
Give it a try and you’ll be pleasantly surprised at just how much flavor indoor lettuce plants can pack in their thin, little leaves. Bon appetit!
How much light does lettuce need to grow indoors?
According to crop scientists, lettuce needs approximately 12–20 hours of light per day to fully grow. If your indoor plants are starved for sunlight, get some LED grow lights instead.
Just don’t keep the light bulbs too close thinking it’ll make the plant grow faster; about 6 inches should do the trick.
Can you grow lettuce indoors year–round?
Yes, with the proper indoor temperature (between 60–70°F). You’ll also need plenty of sunlight for your plants to bathe in; LED grow lights are another valid option. And don’t forget to water your plants regularly!
How long does lettuce take to grow indoors?
If the conditions are just right, it takes about a week or so for seeds to sprout. After that, you need to wait 30–40 days before it’s time for your first harvest.
Note that some lettuce varieties need 6 to 8 weeks before reaching harvestable size.
Can you grow lettuce indoors without a grow light?
You don’t need a grow light if your windowsill can provide at least 12 hours of sunlight per day for your beloved plant. Otherwise, you’ll probably need growing lights for lettuce plants to fully grow at your location.
In fact, LED lights are a superb option as regular light bulbs just don’t have the spectrum that lettuces need to grow. And providing the right amount of light each day is crucial when learning how to grow lettuce indoors.