Hydroponic Lettuce: Guide to Growing


Lettuce is a popular green vegetable, thanks to its versatility. It comes in handy in salads, burgers, and as a substitute for bread. If you enjoy lettuce, it would be a great idea to grow it at home and meet your demand seamlessly.

Hydroponic lettuce is easier to grow than that in the soil. It is more resilient to pests and tends to yield more in a short time.

In this article, you will learn how to grow hydroponic lettuce, including the materials you need and valuable tips to maximize production.

Key Takeaways

  • The variety of lettuce and the hydroponic system are some of the most important things to consider before starting.
  • Hydroponic lettuce requires a specific nutrient mix that is high in nitrogen and potassium.
  • Cool temperatures and a least 10 hours of light are essential for optimal growth and maximum yield.

Hydroponic Lettuce: Getting Started

Before starting a hydroponic lettuce garden, it is essential to keep a few factors in mind.

Choosing the Variety

Lettuce comes in four major varieties, namely butterhead, romaine, loose-leaf, and crisphead. You can choose any of these varieties; however, the loosehead varieties tend to do well hydroponically [1].

This is because, with loosehead lettuce, you can pick leaves as they grow without needing to harvest the entire plant. The picked leaves regrow in no time, prolonging harvest life and ensuring you have a constant supply of lettuce leaves.

Choosing the Hydroponic System

The needs at hand will determine the type of system you choose for the lettuce. If you intend to build a large-scale hydroponic lettuce garden, the Deep Water Culture and Nutrient Film Techniques are most preferred.

With the deep water culture system, you will need to set up a large water and nutrient solution reservoir to accommodate all the plants. You will also need to invest in a water pump to circulate water and an air pump to aerate the pond,

With the nutrient film technique, you can control the nutrient levels, thanks to the design. The shallow channels allow a constant circulation of nutrients whereby water drains back to the reservoir by sloping the channels.

The Best Nutrients for Hydroponic Lettuce

It is advisable to use a nutrient mix that is specifically crafted for hydroponic lettuce. This will ensure you provide exactly what your lettuce needs to grow and produce consistently.

A general hydroponic nutrient mix will provide essential nourishment in the vegetative phase of the lettuce without pushing it to the flowering stage.

Ensure the mix has adequate calcium to prevent tip burn. Also, ensure the mixture is high in nitrogen and phosphorous but low in potassium. Lastly, ensure you keep the solution aerated to promote nutrients absorption.

Favorable Environment for Hydroponic Lettuce

How you set up your hydroponic lettuce and the environment you provide will highly affect the growth process, including the yield. It is therefore essential to consider the environmental parameters to ensure a favorable environment for lettuce to grow [2].

Grow Medium

Hydroponic lettuce grows the roots in water; therefore, it is essential to ensure the medium will allow the seedlings to sprout. You also need to ensure the plants will have physical support as it grows bigger. Phenolic foam and stone wool are great alternatives for germinating lettuce seedlings.

Light

Lettuce, unlike most other green vegetables, does not demand a lot of light. 10 to 14 hours or low to moderate light is adequate to facilitate proper growth. It is important to note that growing lettuce in full sunlight can increase the bitterness of the leaves.

If you have red leaf varieties, consider supplementing lighting with grow lights to ensure the leaves get a deep color. But generally, lettuce can yield well growing in a shade or a low-light environment.

See our article on how the color of light affects plant growth to learn more.

Temperatures

Generally, lettuce does well in cooler temperatures. The warmer it gets, the higher the chances of flowering, making the leaves bitter. That said, growing lettuce in a greenhouse, especially in the summer, is not ideal.

FAQ

How Long Does Hydroponic Lettuce Take To Grow?

Surprisingly, hydroponic lettuce grows quicker than that produced in the soil. Naturally, lettuce grows the leaves quickly; but putting them in a hydroponic system charges them to grow faster.

Like other hydroponically grown vegetables, lettuce grows significantly faster. This is because the systems are controlled and crafted to meet the needs of the plants. That means the environment is favorable and efficient to facilitate rapid growth.

The best part is that light, water, temperature, and nutrients are all controlled, ensuring they are at optimal levels to ensure consistent growth of the lettuce.

Varieties like the butterhead and romaine lettuce can take less than four weeks to grow to maturity. Other types like the iceberg can take between six to eight weeks to reach maturity.

How Do You Harvest Hydroponic Lettuce?

Harvesting hydroponic lettuce is pretty easy; unless you are growing crisphead varieties such as iceberg lettuce. With the other types, you can pick individual leaves as they grow.

To harvest, cut off the bigger outer leaves leaving the inner ones to continue growing. Alternatively, you can wait for the entire head to grow and harvest the whole head. The best way to do this is to cut off the roots leaving the head intact [3].

Can You Regrow Hydroponic Lettuce?

Yes, you can regrow lettuce from an already harvested plant. If you pick all the leaves on a head of lettuce and leave it in the hydroponic system, it will continue to grow and produce new leaves. This extends your yields, giving you great value from each plant.

The best approach is to harvest individual leaves as they grow instead of picking all the leaves simultaneously. This will give the lettuce time to develop new leaves, prolonging harvest time.

However, when bolting occurs, the stage where the lettuce shifts from leaf growth to flower, you may need to plant fresh lettuce.

The Bottom Line

If you are new to hydroponic gardening, lettuce may be one of the plants you can start with. Hydroponic lettuce is easy to grow, does not need much care, and takes a short time to develop to maturity. With the tips above, you can start your hydroponics lettuce garden, meeting your household demand for this precious vegetable.


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