How to grow lettuce hydroponically

You have to try this!

If you have never grown anything with hydroponics and you would like to give it a go I would suggest you start with lettuce. For beginners lettuce is the easiest crop to grow.

Once you gain the experience of how to grow lettuce hydroponically you will have the confidence to try growing other things.

If you don’t have a hydroponic system already you can build a simple system by following the information found on my other pages below! These pages open in a new tab so you can come back here after taking a look without the fear of loosing this article.

[Build your Own Hydroponic System part 1]

[Build your Own Hydroponic System part 2]

This will help you get started in growing food without soil.

For the more adventurous person I have a review page where you can check out some building plans. They will help you get started not only in hydroponics but in aquaponics. The review pages are found here for your convenience!

[How to make an Aquaponic System]

[Aqua and Hydroponics Supplies]

What ever you decide to do I hope you will give it a try!

First I will give you an overview about lettuce and then we will get into the “How to grow lettuce hydroponically” part later.

Some of the reasons why I like to grow lettuce.

  • Lettuce is widely used in a variety of salads
  • You can use lettuce in your sandwiches.
  • People put them in their hamburgers.
  • You can put lettuce in your wraps.

As you well know lettuce has a wide variety of uses and I’m sure you could add a few more uses to my reason list above.

Why do I say it’s the easiest to grow?

Lettuce is a cool season crop so it doesn’t require higher temperatures like tomatoes. It’s quite happy growing anywhere between 8 to 25 Celsius (45 to 80 Fahrenheit). As you can see it would be quite happy growing in the average home because the average room temperature falls between its best growing ranges.

It doesn’t take up much room so you don’t need a large hydroponic system. A three or six pot system is plenty because you don’t harvest the whole plant. Just cut of some fresh leaves as you require them.

This is much better than the limp lettuce found in most peoples refrigerators.

Which lettuce is your favourite?

There are so many varieties of lettuce available and I’m sure you have your favourite in mind as you read this.

Grocery stores are usually limited to a small variety of lettuce because they depend on what their supplier produces. Well! I will let you in on a little secret. If you Google “lettuce seeds” you will be as amazed as I was to find out the large variety of lettuce seeds available.

Armed with your hydroponic system and a few lettuce seeds you can now grow lettuce that is not found in your local grocery store. How’s that to impress your friends! The next time they come over for dinner and ask you where you found this delicious tasting lettuce you can say you grew it yourself.

Local bought seeds

In the spring you will find lettuce seeds available for purchase at any hardware stores or garden centers. Here are some that were available at our local Wal-Mart

Grand Rapid lettuce
Grand Rapid

Grand Rapids Lettuce

  • 45 days to mature.
  • 7-10 days to sprout
  • Thrives in cool weather


Iceberg Lettuce

Iceberg Lettuce

  • 75 days to mature
  • 7-10 days to sprout
  • A very popular lettuce it has a delicately mild flavour and thrives in cool weather.


Early Curled Simpson Lettuce
Early Curled Simpson

Early curled Simpson Lettuce

  • 45 days to mature
  • 7-10 days to sprout
  • Very popular leaf lettuce and will withstand hot weather better than other types of lettuce


The fun part is watching lettuce grow!

The time it takes for each lettuce seeds to grow to maturity is found on the packet, though I doubt very much that your lettuce will reach the packet maturity time before you are sampling them.

Lettuce grows much faster in hydroponics. So 20 to 30 days would be about right for you to start sampling your crop a few leaves at a time.

Once lettuce has passed edible maturity its leaves will become tougher, it will lose its shape and try to “bolt”. This is an expression used when lettuce goes to its next phase which is flowering and to produce seeds like all other plants do.

They should be eaten before this happens (unless you want to see a lettuce go to seed.)

Once you get familiar with hydroponics you can start your seed germination at different time periods. This will give you a constant supply of fresh lettuce. When one plant has finished remove it, re-seed and the whole process starts again.

This is how I grow lettuce Hydroponically

I hope by now you have decided to give hydroponics a try and if so you have the three options I discussed at the beginning of this article.

To recap you can buy a ready-made system, build your own system from plans or build the one from my website and adjust to suit your needs.

Let’s assume going forward that you followed my instructions to build the small homemade hydroponic system found at:

Build your Own Hydroponic System part 1 and 2

The growing medium I like to use are the clay pellets mainly because that is what I started with and they last for years. In my other page “Build your Own Hydroponic System part 1 and 2” I show several different types of growing mediums. You can review them and choose one that is available in your area at a reasonable price.

Net pots also come in a variety of sizes but for lettuce a small 2 inch net pot is plenty large enough.

I have also used 3 inch net pot when that is all I had on hand.

Have you decided what type of lettuce you want to grow? If so we can get into the fun stuff.

Simple Germination Method

There are many ways to germinate lettuce seeds and everyone has their own preferred way of doing it.

You can purchase all kinds of germination kits that use Rockwool, which can be found in your local hydroponics store or you can easily find it on Amazon. Rockwool is a germination medium that I would recommend and I have used it successfully for many years.

The following is an alternative method to germinate seeds that I have also used successfully and you may like to give it a try.

This is what I do.

Lettuce seeds sprinkled onto moist clay pellets
Lettuce seeds sprinkled onto moist clay pellets

I pace the empty net pots in the lid of my hydroponic system, then fill the tank with water until the water is about 1 inch or less above the bottom of the empty net pots.

I use clay pellets for my growing medium. I then fill the bottom of one or more net pot to just above the water line in the pot. You only need to germinate enough seeds to fill the remaining unused net pots after germination.

You will see that the clay pellets will become moist above the water line but the water is not visible.

You now sprinkle a few seeds on top of the now moist clay pellets. Yes I know! Some may fall through the cracks and down into the water and drown but seeds are plentiful so no problem.

Lettuce Seedlings
Lettuce Seedlings

As long as the seeds have fallen between the clay pellets and not into the water they should be fine.

Within a week you should see the seeds start to sprout. When they are large enough to handle you can thin the seedling out and transplant them into the other pots. Keep adding the clay pellets to support the seedlings as they grow.

I would always recommend using spring water or those large reverse osmosis bottles found in your grocery store. I would not use city tap water because it usually contains chlorine and other additives.

You will notice too that I have not added any nutrients to the water at this time. Just like babies they are not ready for solid food yet.

Cover the net cups with a clear plastic or glass cup to act as a greenhouse until they get there first real leaves.

This germination method I have used on several types of seeds.

I have tried to simplify one method of how to grow lettuce without soil. So I do hope you will give it a try.

The next question is, what nutrients should I use to bring my lettuce to maturity?

Nutrients basically come in two formulas for the growth phase and then the bloom phase. As I mentioned earlier we will eat the lettuce before it reaches or bolts to the bloom phase. The nice thing about this is  you only require the grow nutrients for lettuce. This provides strong roots to give you healthy plants.

Go to this review page to see what I have successfully use for my plants.

 Hydroponic Nutrients for Lettuce

Thanks for stopping by and happy gardening!!!



  1. // Reply

    I have grown house plants and tomatoes outside in the summer, but I have never tried hydroponics. Your shopping list for building your own system was very complete and easy to follow. You made it sound easy enough to make me interested in giving it a try! Thanks! I will check back on your website for more tips and info.

    1. // Reply

      Thanks Lacy for your kind words,
      Tomato plants are excellent to grow in a hydroponic system. Due to the constant supply of water and nutrients they keep there shape when growing. Tomatoes sometimes loose their shape because of inconsistent watering.
      Thanks for stopping by,

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