At its most basic level, hydroponics is the cultivation of plants without soil. The word hydroponics comes from a mixture of Greek and Latin where hydro means water and ponos means sowing/cultivation. Hydroponics is the cultivation of plants using water as a substitute for soil. Soil is what is known as a growth medium and is not actually essential for plant survival.
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The history of hydroponics
Hydroponics seems like a very new technology, and of course it is if you compare it to the early agricultural societies that emerged 12,000 years ago. But if you look at hydroponics with more modern eyes, you'll realise that it's actually an ancient method.
Hydroponics was first used a couple of thousand years ago. It is believed that the technology was used in The Hanging Gardens of Babylon, in what is now Iraq. In addition, we also know that it was used in the floating fields/gardens of the Aztecs and ancient China, and in fact, it still is today.
During the 1600s, the type of hydroponics we know today really took off. This is when researchers and scientists, such as Francis Bacon, began to investigate and research hydroponics from a scientific perspective. Back then, however, the subject was referred to as hydroponics.
The water cultures were then used in several different biology-orientated experiments.
It was during these experiments that the scientific community came to the conclusion that fertilisers and nutrients were necessary for plant growth, as well as determining exactly which substances were important. This has had a huge impact on agriculture and modern NPK fertiliser. And hydroponics is actually still used in a laboratory setting to research fertiliser variants today.
Later, around the 1920s, American researcher and professor William Frederick Gericke from the University of California became interested in cultivation with water as a growing medium. Using this method of cultivation, he grew a tomato plant almost 8 metres tall, which became a sensation and resulted in a lot of attention for the scientist. He then coined the word hydroponics to describe the method.
Between 1930 and 1950, hydroponics was used by the US military to grow food and crops on remote and inaccessible military bases. This was largely done at the Wake Island military airport in the Pacific Ocean. The military base produced around 40kg of vegetables weekly.
In the last few years, Nasa has probably been doing the most research when it comes to hydroponics. They hope to use it to grow crops for astronauts on future space missions.
Among other things, they have tested it on the International Space Station (ISS) and expect to use it on manned Mars missions. During their research, they have also invented a new type of hydroponics, this new form of cultivation is called aeroponics.
Modern industrial hydroponics
Nowadays, however, it's not only research and research that benefits from hydroponics. Many companies and individuals have started using hydroponics to grow vegetables and herbs efficiently.
Among other things, the company is Nordic Harvest from Taastrup, Denmark, is working on one of Europe's largest vertical farms. A vertical hydroponic farm is a multi-storey hydroponic farm, stacked on top of each other, which allows for a very large production in a relatively small space.
Being able to grow a lot of food in a few square metres is extremely practical because it means you can move food production closer to the demand for food, i.e. the cities.
It is possible to convert existing warehouses, warehouses and other large industrial buildings into vertical hydroponic farms.
Large indoor farms like these are very beneficial for the green transition, as they ensure that we don't have to import and transport food over long distances. In addition, they can produce all year round, making it possible to enjoy fresh, locally grown lettuce heads even in the middle of winter.
But the climate benefits of hydroponics are even greater. A hydroponic farm is a closed system, meaning nothing can seep into the soil and go to waste.
All water and fertiliser can be reused in the system, resulting in a drastically lower amount of water and fertiliser needed from sowing to harvest than it takes in conventional soil-based agriculture. In fact, 95% uses less water than conventional farming.
Being a closed system also means that it's possible to run the farm as a cleanroom. A cleanroom, also known as a clean room, is a room designed to be as isolated from the outside world as possible. It is therefore airtight, where all air in the building is cleaned before it enters, in addition, cleanrooms also require staff to change clothes before entering.
The advantages of a cleanroom or semi-cleanroom are that you maintain a very low concentration of airborne particles and external contaminants. This guarantees that the risk of plants becoming infected or infected with plant diseases is absolutely minimal.
Therefore, there is no need to use pesticides and the like, which is good for both the people who will eat the plants and the environment.
Hydroponic growing for individuals
However, hydroponic growing doesn't only benefit businesses and Denmark on a national level. As a private individual, you can also grow food hydroponically and benefit greatly from it. Here at plant lights, we sell equipment for large commercial farms, but also for individuals like you.
You can benefit greatly from having your own hydroponic "mini-production". For example, with an indoor "smart-garden" kitchen garden, grow fresh herbs directly in your kitchen all year round, even in the deep winter months.
When growing plants hydroponically, there are a lot of small differences from conventional growing, all of which make your life a little easier. For example, you don't have to water your plants nearly as often. Because hydroponic growing is done in water and not in soil, there is significantly more water available to the plant, which means you can go longer between waterings. It's also less messy as you don't risk spilling soil and mud in your home.
Above all, hydroponic cultivation provides a greater yield. So when it's time to harvest your plant, you'll have more "fruit" than you would if you grew the plant normally. In addition, it will also get ready faster. Hydroponic plants grow significantly faster. In fact, you can grow an entire head of lettuce hydroponically, from seed to finished plant, in just about 3 weeks.
How hydroponic cultivation works
Here you can read almost everything you need to know to understand how to grow plants hydroponically. When growing plants hydroponically, there is no need for soil, but there are a lot of other things that are strictly necessary. Plants have many needs, and in many ways, the whole point of hydroponics is to fulfil all these needs as well as possible. Thanks to the scientists who experimented with hydroponics back in the 1600s, we know exactly what those needs are.
As you may remember from primary school, plants perform photosynthesis. Photosynthesis is the process by which the plant's chloroplasts (leaves) convert light, water and CO2 from the air into oxygen and glucose for the plant itself. From photosynthesis, we can already conclude three things that we need to make sure are available to our hydroponic plant if we want it to grow. Light, water and air (CO2).
What is hydroponics - The Growth Medium
Growing media... Unless you already know a lot about growing plants, growing media is probably not something you've heard much about. But hopefully we can change that. A growth medium is basically the material in which "growth" takes place. For a normal potted plant, its growth medium is soil. It is the soil that holds the plant's roots in place, and it is the soil that stores the water and nutrients that the plant needs.
However, soil is not the most efficient way to grow plants. In addition to efficiency/speed, soil is also not sterile, which increases the risk of diseases, pests and fungi spreading to your plant if you use poor soil. For this reason, it's generally best to use a sterile growing medium if you want to ensure a perfect harvest.
However, hydroponic cultivation is even better than sterile growing media. With hydroponic cultivation, there is no need to use a growth medium at all. Instead, you simply have water with dissolved nutrients that are in direct contact with the plant's root system. However, it is important not to add too much water. If the water level gets too high and comes into contact with the "seed", i.e. where the plant transitions from root to plant, you risk drowning the plant. However, the water level should not be so low that the roots cannot reach the water.
If that sounds too difficult and you'd rather just experiment a little with growing plants in media, read our article that brings together the many different media types.
What is hydroponics - Light
Artificial light is not part of hydroponic growing as such. However, there are many good reasons why it is often involved when talking about hydroponics. In principle, you can easily grow hydroponic plants outside with the sun as the only light source. However, this does put some limitations on you when it comes to the period of time you can grow. Because of hydroponics' amazing growing characteristics, it is very suitable for indoor growing, especially with a little help from artificial light.
It is therefore advantageous to purchase an artificial light source designed for plant cultivation, also known as a grow lights. With a grow light, it becomes possible to grow plants all year round, so you can be completely independent when it comes to the sun and the seasons of the year. A grow light is a special lamp made with extra high brightness, in just the right wave length for plants to photosynthesise under. Learn more about lights for growing plants.
What is hydroponics - Nutrients
But that's not all they need - it would be easy if it were that simple. Plants also need many different nutrients. Usually, the primary nutrients, the ones plants need the most, are nitrogen (N), phosphorus (P), potassium (K), sulphur (S), calcium (Ca) and finally magnesium (Mg).
When growing plants conventionally, you typically don't have to worry too much about adding nutrients. Normal soil often contains many of these substances naturally. However, this is not the case when it comes to hydroponic growing, as water is largely sterile. Fortunately, you don't have to find all the substances individually and measure and mix them in the right proportions yourself. That's how it was back in the old days, but nowadays it's a lot easier.
Here on plant lights, but also many other places, it is possible to buy fertiliser, which contains all the nutrients the plant needs for optimal growth in a hydroponic environment. Personally, we recommend fertiliser from the BiG plant science brand. All BiG plant science fertilisers are Danish produced and designed specifically for Danish water conditions. See more Benefits of BiG fertiliser plant science.
Hydroponic equipment
Congratulations! You are now ready to start growing plants hydroponically. Here at plantelys.dk we are experts in hydroponic growing, so if you have any questions, feel free to give us a call. Find us contact details here
You can also take a look at our Equipment for hydroponic growing. Or maybe read a little about microgreens? Micro greens like hydroponics, is a new and exciting form of cultivation with great potential!
