How to grow Hydroponic Green Onion: Growing Guide

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Hydroponic Green Onion

Green onions are a great root vegetable to grow using a hydroponics setup. Growing hydroponic green onion need only the basic setup for them to thrive. In the details that follow, we are going to explore exactly what you need in order to make your hydroponic green onions grow and thrive in a short amount of time.

green onions growing

Hydroponics Setup

Hydroponic GardenA hydroponic garden has many advantages to it because all you need is a water reservoir, with maintained pH levels in order to grow amazing hydroponic gardens. Hydroponic systems are ideal because of the decreased fungal diseases that your vegetables are likely to encounter. 

Using hydroponics is an easy method to grow crops, especially green onions. Before long the green onions will have little green sprouts forming, and your hydroponic system is likely to increase the growth rate of the green onions because they have access to such rich nutrients in the water. 

If you’re new to hydroponic gardening, you might be picturing an extravagant setup and hydroponic technique, but it doesn’t have to be complicated in order for your garden to grow and thrive. In fact, together, we are going to explore some different hydroponic systems, which might work out well for you. 

I have my favorite version of growing hydroponic green onions, which is extremely easy, and I am very excited to share it with you. Stay tuned for all of the different types of hydroponic gardening you can use to grow green onions. 

But first, before we dive into the different hydroponic systems, let’s first look at the types of green onions you can grow in a hydroponic garden. 

green onions

Types of Green Onions to Grow in Hydroponics 

There are a few different types of green onions you can grow in hydroponics. Some types of green onions will require more items in order for them to be able to grow, but if done right, they can all go in thrive in a hydroponic garden. 

The main types of green onions that you can grow in a hydroponic garden are green onion bulbs, green onion seeds, and green onions purchased from the grocery store. These are the main kinds of onions that are grown in a hydroponic garden. 

Green onion bulbs are usually green onions that are purchased in a small bulb sized, usually as an onion set. These are the types of green onions that can be purchased in the spring from a garden store.  

Green onion seeds come in a seed package. These can often be found at your local grocery store, gardening store, or even farm store if you have one nearby. This is when you take a seed and grow green onions from the seed.

The last kind of onions can actually be purchased from the grocery store. In the produce section, you’ll often find bunches of green onions that are ready to use in your recipes. These green onions are often held together by a rubber band, and ready to use. Believe it or not, the roots from onions can also be grown in a hydroponic system.

Now that you know the three main ways you can purchase green onions to grow in your hydroponic system, let’s look at specific hydroponic systems and how they work. 

Hydroponics System

There are three main hydroponic systems that you can choose from to grow your green onions in. The three main systems include the deep water culture systems, nutrient film technique, and the Kratky method. Let’s first look at the deep water culture systems. 

Deep Water Culture Systems

Essentially, deep water culture systems are when a plant is suspended so that the roots grow in a well oxygenated water solution that is loaded with nutrients to help the plants grow. Think three parts here, water, oxygen, and nutrients. The entire plants are not immersed in the water and nutrients mixture, rather just the root system. 

It gets its name because usually they are grown inside a container, which can contain a lot of water, hence the name “deep water”. Because of the high volume of water a container contains, it requires less work to monitor the nutrient value inside of the container because the water and nutrients last longer.

For the system, you can use any type of container, often it’s a bucket or a tote, there are a lot of different options when it comes to the type of deep container that the hydroponic spring onions are grown in. They will also need nap pots with perlite to suspend the green onions so that they are not completely immersed in the water and nutrient solution.

Another option is to use oasis cubes. In some cases, the water is simply tap water, which is combined with a nutrient solution concentration in the water, making it very nutrient rich. A grow light is also needed, as well as a pump to circulate the water. 

When functioning and deep water culture system can easily grow green onions, either from seed or from a bulb form.

green onions in a glass

Nutrient Film Technique 

The next type of hydroponic system that is another popular technique to use is the nutrient film technique. This is typically made from long shallow channels, which are slightly tilted. This allows small nutrient films of water to flow over the green onions’ root system. The water mixture is very nutrient-rich water, making the root of the green onions thrive. 

The green onions themselves are still grown in net pots so that the bulbs themselves stay above the water, but the roots grow down to reach the nutrient rich water mixture.

There are significant differences between the nutrient film technique and the deep water culture systems. One of the main differences is that the deep water culture system is a hydroponic system with deep water for the roots to grow into, as opposed to the nutrient film technique, which allows the green onions roots to grow into a small amount of water, but a very nutrient rich mixture of water and nutrients. 

These two hydroponic systems are also arranged in different positions. Often the nutrient film technique will use long narrow systems, like a PVC pipe, which can easily be tilted at an angle for the water to flow through. 

Kratky Method

The Kratky method is yet another hydroponic system in which green onions can grow. There is a little difference between this method in the previous two methods for growing green onions. The other two methods had water and nutrients that circulated. Typically, this method does not incorporate any electricity or water pump while the plants are growing. 

For this method, a growing tray, such as a plastic bin is used as the hydroponic container. Then the green onions, bulb onions, or immature small onion bulb, are placed into a growing medium and sustained so that the roots of the green onion are submerged and added to clean water, as well as a nutrient mixture.  

This method does not usually incorporate aerated water. Instead, it remains stagnant. It is done with less water where the green onion roots reach down into the water and grow in stable nutrient-rich water with stable pH values. 

This crop of hydroponic onions will need to be harvested as soon as the growing cycle is over, since the water will be nearly depleted of its nutrients. This method of growing hydroponic onions is much more hands off, and the other hydroponic methods.

cut green onions

Hydroponic Green Onion: Kitchen Straps

The last option, and one of my personal favorites is to grow hydroponic green onions using kitchen scraps. That’s right, these are mature green onions that you can purchase from the grocery store, then cut off and regrow them. 

This is an excellent choice because it is very easy to do. You don’t need any complicated hydroponic system in order to regrow the green onions, and they provide you with a continuous supply of delicious green onions. 

To start off, cut the green onions halfway so that the dark green part of the green onion is removed, leaving the light green and white bulb intact. Take the leftover green onions, with the white bulb at the bottom, and place it into a jar of water, fill it part way with cool water. The white roots of the plant should be completely immersed in the water. 

green onions with a knife
green onions on cutting board
bottoms of green onions

Place the jar of water with green onion cuttings into direct sunlight, such as a sunny windowsill. Within a few days, you will begin to notice the new growth of green onion plants. Continue to keep an eye on the root vegetables until they are approximately half-grown onions. 

As the onions grow, when they are approximately half-grown or are thin green onions, you can move the onions into another type of hydroponic system, listed above such as the deep water culture systems, or the nutrient film technique. 

Or you can even transplant the half-grown onions into a pot with soil. Plant them so that the white bulb of the green onions is covered in soil, then continue to grow them in a warm sunny location. This is a great way to have a continuous supply of regrown green onions. 

The next time you have kitchen scraps of green onions left over, keep this hydroponic method in mind and give it a try. It’s one of my personal favorites and I hope you like it too! 

Green Onion Health

As you grow hydroponic green onions, a few things to keep in mind are their need for sunshine or a grow light, and the warm temperature range that they prefer is best.

Sunlight. Green onions enjoy full sun, so if you are growing them in the house, keep in mind that they will either need to be placed into a window with a lot of sunlight or grown under a grow light. 

Temperature Range. Green onions also like to be warm, so as they grow, try to expose them to high temperatures. We will have the best time when they are at their ideal temperature range which is between 65 and 70°F (18.3 – 21.1°C).  

Outdoor Hydroponic Systems

Keep in mind that not only can hydroponic systems be used to grow green onions inside, but they can also be used to grow green onions outdoors in a hydroponic setup. If they are grown outdoors, green onions will likely do better in high humidity, or in a greenhouse, where they are also exposed to warm temperatures and sunshine. 

Best Hydroponic System

What is the best method for growing green onions in a hydroponic system? Honestly, it all depends on how much space you have, how much time and energy you have, and if you are just looking to start out and dabble in hydroponics, or if you have experience with hydroponics.

If you are just starting out, then you might want to begin by trying to grow your own green onions using kitchen scraps. Or you can also try out any of the other hydroponic methods above. Feel free to have fun and see what you like the best.

Hydroponic Cultivation of Green Onions

Growing hydroponic green onions is a way to consistently have a healthy supply of green onions available for your use. Some hydroponic setups are more extensive and in-depth than others. I hope that this has helped you learn more about hydroponic gardening, and how you can grow your own green onions in a hydroponic system. 

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About the author

Hi! My name is Faith, I am the creator behind My Sweet and Saucy. I have so many different things that I enjoy doing, and this is my space to share them all with you. I really hope you enjoy it! Thank you so much for stopping by!

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