Hydroponic lettuce is easy to grow and the perfect beginner crop. It’s started from seed and carefully transplanted once the roots have taken hold. It thrives with nitrogen and potassium fertilizer. Some common varieties to grow include Butterhead, Romain, Little Gem, and Iceberg.

Why should you consider growing hydroponic lettuce?

Leafy greens and hydroponic systems are a match made in heaven. Lettuce is known for how fast it grows and how much just one head produces. 

Lettuce is the perfect starter plant for beginners. There’s not too much to know or an excess of things that could go wrong.

Similarly, since growing lettuce hydroponically doesn’t take up too much space, it can be scaled commercially very easily. Hydroponic crops are incredibly popular among producers, especially leafy greens.

Which varieties of lettuce are commonly grown hydroponically?

Here are some common hydroponically grown lettuce varieties:

Butterhead. Butterhead is named after its buttery flavor in lettuce. Butterhead lettuce plants run colors ranging from red to bright green to dark green. The leaves are slightly ruffled.

Romain. Romain is one of the most well-known types of lettuce with a defining crisp texture. It’s one of the sturdier lettuces on the market.

Little gem. Little Gem is the perfect middle ground between Romain and Butterhead lettuce.

Iceberg. Iceberg lettuce is what you think of when you think of a typical head of lettuce. 

How to Plant Hydroponic Lettuce

Hydroponic vegetables growing in greenhouse

To start planting hydroponic lettuce, start germinating the seeds in a fitting growing medium like perlite, coconut fiber, lightweight clay aggregate, or rockwool.

It’s unlikely that all of your lettuce seeds will successfully germinate. You can expect closer to 3/4 of them to succeed. 

To germinate the seeds, fill your trays up with one of the aforementioned growing mediums. Add water slowly so that the trays are moist but not waterlogged. Add around three seeds to each plug and cover slightly with medium.

Keep misting the seeds regularly so that the growing medium stays moist. When the lettuce has a couple mature leaves and roots that protrude from the bottom of the medium, they’re ready to be transplanted. They should be around two inches tall and it will probably take somewhere between 14 and 21 days.

To transplant your seedlings into your hydroponic system, be careful not to disturb the new stalks too much. Very lightly and gently loosen up the roots with your fingers. Carefully put each seedling in its spot. Again- carefully- put the roots through the slats so they can reach the nutrient solution.

How long does lettuce take to grow hydroponically?

One of the best things about hydroponic lettuce is how quickly it grows. Lettuce already grows quickly in traditional gardens, but hydroponic systems speed that up even further.

Pretty much all vegetables grow much faster in hydroponic systems than they do otherwise. This is because all aspects of the environment are completely dialed in to optimize growth.

Certain varieties of hydroponic lettuce are even ready in just three to four weeks.

Caring for Hydroponic Lettuce

Hydroponic lettuce in farm

Growing hydroponic lettuce is incredibly easy and doesn’t require a lot of maintenance. Let’s talk about some of the aspects of caring for hydroponic lettuce.

The Best Grow Lights For Your Hydroponic Lettuce

Light is measured by a daily light integral. This is calculated using photosynthetic photon flux density, aka the amount of light that the plants need within the wavelength. But most growers don’t go so far as to worry about that and just focus on getting their plants enough lighting.

10 to 14 hours of low or moderate light is sufficient. Too much light can lead to bitter plants, while too little can lead to slow growth. You want adequate light without overdoing it.

Darker varieties don’t get as colorful with low light, so if you notice that the color of your lettuce isn’t as deep as you’d like, you may want to add some supplementary lighting.

What can I feed my hydroponic lettuce?

Feed your hydroponic lettuce a high-quality nutrient solution and purified water.

What is the best nutrient for hydroponic lettuce?

Hydroponic lettuce needs nitrogen because nitrogen stimulates leaf growth. It also needs potassium to prevent wilting and grow strong structures. 

Temperature and Humidity

When you grow hydroponic lettuce it likes a cool temperature below 75 degrees F. This is because lettuce is a cool season crop and warm temperatures can cause your lettuce to taste bitter.

During the day, temperatures ranging from 68 to 75 degrees F are ideal, while you can drop the temperature to 60-65 degrees F at night.

Harvesting Lettuce

Periodically harvest your hydroponic lettuce leaves as they grow or as you need them. When you harvest the large leaves on the outside of your plant, the head will continue to grow new leaves on the inside.

When you do this, you won’t have to constantly replant lettuce because it will naturally regrow.

Lettuce can keep regrowing for quite some time until it decides to bolt. Once your lettuce bolts, it’s time to start anew.


Clearly, hydroponic lettuce is a big winner. It doesn’t take up too much space and you’ll have a 40% higher yield than if you grew the lettuce in soil!

Nothing’s worse than needing leafy greens and not having them. Growing lettuce plants hydroponically is the perfect solution.