If you have a passion for gardening vegetables, you must be aware of the non-conventional ways. Growing vegetables hydroponically is one of them. It is a very common and widely used technique with many vegetables; however, we have limited ourselves to hydroponic onions for this article.
Whenever we think of hydroponic onions, we see an image of leafy green outgrowths extending from a container of water building up in our minds.
Although the hydroponic technique is more common for cabbages and lettuces, it has recently great scope for root vegetables. For a short description, the hydroponic technique refers to growing vegetables in a liquid of nutrients. Some various methods and systems are adopted to achieve the desired results.
Why should you grow hydroponically?
If you want to fulfill your love for gardening by keeping your place tidy and manageable in the meantime, switching to hydroponic growing techniques can be really helpful.
This will satisfy your desire to grow vegetables and free you from the hassle of routine upkeep responsibilities such as tilling, mowing, etc.
Growing in an artificial growth medium with saturated nutrients speeds up the growing process, and you can have fresh vegetables inside your house in no time. Furthermore, how enjoyable is this that you can have hydroponic green onions just a few steps away from your kitchen? Isn’t it satisfying?
Growing Hydroponic Onions
Onions are one of the hydroponically grown vegetables where you can start from the seeds or the bulbs. Below we have mentioned some simple and easy steps that you can follow to successfully grow onions hydroponically. Don’t worry if you have not done it before because there is no rocket science involved. You can easily manage them with these simple steps. So what’s stopping you from planting your own onions?
Select the right spot
The first step in growing your vegetables hydroponically is selecting the right spot for your setup. When you are growing onions hydroponically, you can choose to grow them either indoor or outdoor. If you decide to grow them indoors, you need to make sure that the setup is out of reach of children; otherwise, any disturbance could result in the destruction of everything. However, the indoor settings need to be tidy and well-organized so that they don’t look odd with your interior design. You can also go with larger outdoor setups if you like.
Grow from a seed or bulb
There is one more benefit of growing onions hydroponically you can have the liberty to start from either the seeds or the bulb. With the seeds, you can simply disperse them in growth until they start sprouting and then transfer them to the hydroponic culture.
If you want to go with the bulbs first, set up the bulbs carefully by partitions or separations in an external medium. When the little sproutings began to show themselves, very carefully transfer them to the hydroponic setup for efficient and manageable growth. Placing the bulbs directly into the growth medium won’t produce appreciable results as the bulbs would not be able to adjust properly.
Grow the bulbs in the suitable accessory medium
When you choose a growth medium for onion bulbs so that they can grow to a stable length before putting them into the hydroponic setup, you have to be very careful in your selection. There are many mediums you can choose from, but the most effective and efficient are composite plugs, plain soil, or Rockwool.
The selection of the right initial growth media will ultimately determine the growth rate of the bulb in the hydroponic setup. So, make sure you get the right quality of any of the above-mentioned options.
Place your seeds in the growth media
When you are beginning with the seeds, you can not directly place them in the growing setup too, because they need less water and no nutrients initially. There are three methods commonly used to irrigate the seeds
- Watering the seeds
- Soaking the seeds for a while before placing them in the actual medium
- Wetting the seeds before placing them in the medium
You can choose any of the methods depending upon your suitability. As seeds are tiny, you need to be very careful not to wash them away while irrigating them.
About the nutrients, if you follow the myth of more food means greater health, you will end up messing things up. The seed’s embryo has an ample amount of nutrition for the plant’s initial growth, and therefore an extra dose of nutrients would, in fact, be dangerous.
Do not use fertilizers
The rule mentioned above also stands for fertilizers. If you use fertilizers, you will actually do more harm than good. Fertilizers contain chemicals that can even burn the seeds or the newly erupted seedling. After putting so much effort, the last thing you would want would be to see your plants die, so refrain from adding unnecessary items in the growth medium.
Your onions would instead appreciate a little extra supervision, and you can check if they are irrigated properly and secured in place.
Place the seedlings in a growth medium
After the little sprouting starts to show, now is the time to transfer your seedlings to the hydroponic setup. You don’t have to waste the growth medium and can move the seedlings along with the growth medium in the setup.
Prepare your water reservoir
When making a hydroponic setup, make sure your water reservoir is 6 to 10 inches deep for better growth. Water is the critical element in the hydroponic culture, and therefore a sufficient amount is required to fully dissolve all the nutrients.
Types of Hydroponic Setups
As onions are a root crop growing them hydroponically is somewhat tricky than other leafy crops. So, you need to be a little extra careful with the medium you choose when growing hydroponic onions. Other than that, you need to be vigilant about the essential requirements such as proper aeration, light, and nutrients. The most commonly used growth mediums are:
- Wick Systems
- Deep Water Culture (DWC)
- Nutrient Film Technique (NFT).
- Kratky method
You can decide from one of them and prepare them accordingly to produce a good yield.
Wick system is one of the oldest methods used for growing hydroponic vegetables. It makes use of the passive hydroponic method. As the name suggests, the nutrients are transported to plants’ roots via a wick such as a piece of rope. It is an ideal system for growing smaller varieties of onions efficiently.
Nutrient Film Technique
It is best known for growing vegetables in lesser space as is required in other growth techniques. Hydroponic green onions require a plentiful amount of space, and you have to make sure that each seedling gets the right amount of light and air. In the nutrient film method, the onion seedlings are placed in channels, and the roots come in direct contact with the nutritional liquid that is pumped into from a larger reservoir beneath. The channel has two openings so that when it has passed through the roots, it falls back to the main tank.
The roots are not to be entirely submerged in the nutrient medium which forms a film around them. The formation of the film is what separates this method from the deep culture technique. The plants are placed inside the channels using simple or net pots. You can harvest the onions one by one when they are fully matured.
Deep Water Culture technique
The deepwater culture technique is one of the most efficient techniques in growing hydroponic onions unless you are planning to produce large quantities. Especially if you are a beginner, we recommend you begin with this technique. It is easy and simple and requires much less trick.
It involves no other complications other than the fact that you need to use a large-sized hydroponic pot so that the onion can fairly grow large and do not get stuck inside. To begin with, you need a pot that will hold the nutrient solution. Unlike the Nutrient Film Technique, the roots of the plant are completely submerged in the solution in this method. The air is pumped inside through a pump for proper oxygenation of the roots and thus the plants.
The pumping of air also prevents the roots from drowning in the water. This fact takes almost every new hydroponic gardener by surprise, but it is actually a thing to take care of. About the setting, you just have to place your plant in a net pot and adjust it over the reservoir so that its roots are submerged in the nutrient solution.
The Kratky method is a combination of growing and preserving techniques. You might have seen vegetables growing in a jam jar filled with water for a science project or as a decoration in the corner of your biology lab. In this method, a half-grown onion is placed in water, the onion grows larger and becomes leafier with time.
Some Important Factors to Take Care of
As we are replacing natural ways of gardening, we need to be careful to provide all the requirements properly.
Proper nourishment is the key to a healthy yield, but in the case of hydroponic onions, it’s better not to supply them with nutrients initially. Firstly, the embryo has enough food for the growing seedling for the initial days, and secondly, the roots would grow longer in search of food when the nutrients are not readily available.
This will form an efficient absorption system with more extensive and stronger roots forming a base. Larger roots absorb a larger amount of nutrients leading to faster growth and healthier yields. As your crop type is a root crop, you should add root growth-oriented nutrients.
The most crucial nutrient here is nitrogen, but you may also not want to stuff the culture with nitrogen otherwise, that will lead to less foliage on the bulbs. Less nitrogen will hamper the strength of roots and shoots.
The optimum pH range for growing hydroponic onions is 5.5 to 6.5. The pH of the hydroponic setup is measure and maintained after adding the nutrients. A sudden change in pH can be very alarming for growth, so check the pH regularly.
Whether chlorinated water is not a must to add, it can be used to regulate pH in case of fluctuation from the normal range. To add chlorinated water, you first need to allow the water to stand for an hour to dissipate chlorine.
Hydroponic onions require sufficient amount f sunlight to germinate and grow properly. You need to make sure that they get full daylight to prevent them from dying. You need to be more vigilant when growing indoors because then you have to make arrangements for them to get proper light.
like traditionally grown onions, hydroponic green onions require just the right amount of heat to grow. You need to ensure that you provide a temperature between 65 to 70 F for the onions to thrive and flourish. Too low and too high temperatures will affect the hormones and enzymes inside the plant, impacting the growth rate.
Air is an essential growth factor for hydroponically grown plants. As they are grown in water and retain a lot of moisture, they are at risk of getting bacteria and mildews if the air circulation is not proper. Good ventilation is the key to keep these harmful entities away. There are several ways of ensuring adequate air circulation, such as exhaust fans, etc.
Aeration refers to the supply of proper oxygen to roots, and it is a vital factor for healthy growth. Itt helps the roots in the efficient absorption of nutrients.
As much as you think that growing hydroponic onions is very difficult, if you follow the above-mentioned guidelines and all the requirements properly, you will get healthy onions in 4 to 6 months from seeds and 80 to 90 days from bulbs.