Growing Lettuce Hydroponically

Growing lettuce hydroponically is one of our favorite ways to get started on indoor farming. Leafy greens and other lettuce varities are super adaptible and can thrive in a water-based environment. They make a beginner-friendly crop for first-time hydroponic growers. Also, having versatile vegetables on hand year round is a huge motivator for devouring more greens.

Remember: hydroponic gardening is a type of farming without soil. Nourishment is given to the plants through light and added nutrient blends that include potassium, nitrogen, and phosphorus. At Little Furrow, we use Lettuce Grow for our farmstand and plant orders.

How to Care for Hydroponic Lettuce

Thankfully, growing lettuce hydroponically is an easy way to get started. Depending on the specific varites of lettuce that you plan to grow, you’ll want to tailor your hydroponic stand’s conditions to be optimal for those plants.

Water

Keep your hydroponic stand watered consistently. Lettuce Grow suggests setting an automated timer to water your plants every fifteen minutes once an hour throughout the day. At night, it suggests letting the timer rest for 165 minutes in between each fifteen minute watering period. For warmer climates, (such as growing outdoors) water more frequently throughout the day and night.

Temperature

If you’re growing lettuce hydroponically indoors, the temperature can remain at a comfortable household temperature—somewhere between 60°F and 75°F. Most lettuce isn’t super picky. If you’re planting outside, you want to make sure that the temperature isn’t dropping too cold at night. With less soil for these plants to be protected from cold in, their roots will struggle to stay strong. Some people may find bringing their Lettuce Grow indoors for winter and outdoors for summer works well with their climate. Find what works best for you.

Light

The most important nutrient for a hydroponic tower is light! If plants are kept outside, make sure that they’re recieving at least ten hours of light a day, and up to eighteen hours when they are first developing. If planting inside and utilizing grow lights, keep lights on for 14–17 hours each day. If the light bothers you, set a timer to have the lights come on at night.

Nutrients

The primary nutrients that hydroponic lettuce needs are potassium, nitrogen, and phosphorus. Other nutrients it needs are calcium, magnesium, and sulfur. Balanzing out all of these nutrients is a bit convoluted, which is why we suggest going with Lettuce Grow’s Nutrient A and Nutrient B mix. Mixing in a few of these compounds into your water base will give your plants everything they need to flourish.

Maintaining Roots

Alongside adding regular nutrients to your hydroponic tower about once a week, take a look at the roots of each of your lettuce plants. Keep the roots trimmed with scissors to about two inches in length. Otherwise, the roots will tangle up with one another, and potentially even your hydroponic system.

Mainting pH

To keep your plants happy, maintain a pH level of 5.5–6.5. Keeping the pH balanced ensures that your plants can prosper, produce fruit, and be protected from disease. No matter how consistent your water, light, and how wonderful your nutrients, having an out of balance pH can prevent your plants from absorbing the nutrients they require. So, about once a week, test your pH and make sure that your lettuce is ready to absorb everything it needs.

Interested in growing sprouts? Learn the basics of jar sprouting for beginners.

Different Varieties of Hydroponic Lettuce

Depending on the leafy greens you eat the most of, you can grow lettuce hydroponically that you are excited about eating. Some of our personal favorites are: arugula, escarole, endive, iceberg, looseleaf, and romaine.

Learn more about the types of plants to grow hydroponically. Just like lettuce is a great starter, consider adding spinach, kale, parsley, cilantro, and a few flowering plants into the mix. Unlike outdoor gardens, hydroponic plants don’t compete for the soil’s nutrients, but many diverse plants can grow alongside one another in harmony.

How to Harvest Hydroponic Lettuce

To maximize the life of your hydroponic lettuce, harvest it correctly. To harvest lettuce, pinch off leaves about an inch from the crown of the plant. This way, the plant will produce more and more lettuce. When it comes to harvesting things like arugula and herbs, use scissors to trim the produce down without cutting away the base of the plant. In a similar vein, learn how to grow microgreens and how to harvest your stems.

How to Store Hydroponic Lettuce

One of the coolest things about hydroponic lettuce, is that it stays fresh for longer than soil-grown lettuce. For best results, follow the steps above, then store your lettuce in a glass container in the crisper drawer of your fridge.

Now that you know the basics of hydroponics, you can get started on growing lettuce hydroponically. Next up: learn how to prepare a fall garden. It’s as easy as sowing a few seeds toward the end of your summer growing season. Happy planting!

Answers to Your Questions About How to Grow Lettuce Hydroponically

How long does it take for lettuce to grow hydroponically?

It takes about six weeks for lettuce to grow hydroponically, but it may take up to eight weeks. Some lettuce varieties can grow to completion in as few as four weeks.

How do you harvest hydroponic lettuce so it keeps growing?

You must cut the outer leaves only and keep the center of the lettuce plant in tact to keep the hydroponic lettuce growing for multiple harvests. If executed carefully, you should be able to stretch one lettuce plant to reap at least three harvest cycles.

Can you regrow hydroponic lettuce from the grocery store?

Technically, yes! It takes a lot of time to regrow hydroponic lettuce from the grocery store. If you place the lettuce stem in a cup of water and store it in a sunny windowsill, and dump the water with fresh water every few days, after days and weeks you’ll start to see the lettuce grow again from the center of your lettuce base.