Hydroponic systems are a way of growing plants without using soil or compost. They are becoming increasingly common in the agricultural industry and are used in the growing number of urban farms, but can also be incredibly useful for growing at home.
What Does a Hydroponic System Look Like?
In a hydroponic system, all the nutrients that soil would provide are given to the plant through the water. It is a system commonly used in commercial glasshouses for growing salad vegetables but is also useful in growing situations where compost or soil would be too heavy or bulky, such as roof gardens and living walls.
Sometimes the roots simply dangle in an ever-moving aerated stream of water and diluted fertiliser, and sometimes an inert growing medium, such as rock wool, is used to anchor the plants.
Hydroponics at Their Simplest
Many people will have had a go at growing hydroponically without even realising it. The old childhood activity of growing cress “hair” from an eggshell “head” stuffed with damp cotton wool is essentially a form of hydroponic growing.
Advantages and Disadvantages of Short-Term Crops
Hydroponics has many benefits. There is no messy compost and, especially when used in commercial environments, the nutrient balance for the plants can be adjusted to the perfect level, depending on the maturity of the crop and even the daily weather.
Once the system is in place, it also cuts down on costs. Lush growth can be quickly achieved due to the watering and feeding system. The use of artificial light means that crops can even be grown underground, which has the potential to revolutionise urban food supplies.
Disadvantages include the environmental cost of the growing media, many of which are not biodegradable, and the initial capital outlay. The average home isn’t going to be able to convert a room into a greenhouse using LED lights, heating fans, water circulation and feeding pipes just to grow a bit of salad for dinner! However, many small-scale set-ups include lighting options for gloomier kitchens. These off-the-shelf products are ideal for a windowsill or desk space and come with full instructions.
Creating a DIY Hydroponic System
Have a go at creating a home system using a bit of DIY.
The plants will need a container (such as a length of guttering that is higher at one end than the other).
They will also need a substrate (rock wool, perlite or similar) for their roots.
Water and diluted fertiliser can be poured into the guttering and allowed to flow down and out. A more complex system could collect the run-off in a tank and pump it back to the top.
You can find books on the specifics of hydroponic growing to help you, or seek out further guidance online. Recommended books include “Ditch the Dirt: How to Grow Beautiful, Edible, Hydroponic Plants at Home” by Rob Laing (Dovetail March 2018). Online websites include www.ikea.com, www.seedpantry.co.uk and www.homehydrosystems.com.
What to Plant
For growing some salad leaves, such as lettuce, rocket, mizuna and mibuna, hydroponic systems are a fun experiment. If there is sufficient space, they can also be used to grow tomatoes, cucumbers, chillies, peppers, annual herbs and wheatgrass.
Greenhouse lettuce can quickly be grown in a hydroponic system, using a mineral and nutrient mixture to feed the plants. The most commonly used method is that of the nutrient film technique. This is a closed system, which means that any surplus nutrient solution is recovered after use, ready to be recycled.
This popular green salad crop is also known as arugula, and both the perennial and annual varieties are suitable for a hydroponic system. They are highly productive plants and can be harvested weekly to encourage further growth. Rocket has a lower light requirement than other salad vegetables, making it ideal for a tired hydroponic system.
This Japanese mustard plant is often found in commercial salad leaf mixes but is incredibly easy to grow at home. Being a small, compact plant makes it suitable for those with limited space, and it will sit happily alongside other salad crops, using the same nutrient formula as that of lettuce or rocket.
Mibuna is very similar to mizuna but has a more intense mustard flavour, and different shaped leaves. It is easy to grow and continues to thrive, even when neglected. The plant can endure extreme cold but doesn’t tolerate heat particularly well. It is ready for harvesting in as little as three weeks, and the leaves can be hand-picked or cut with scissors.
Although it is possible to grow tomatoes using a hydroponic system, it is more expensive than the conventional method. They require a material which is strong enough to support their roots, such as rock wool, coconut coir or perlite. The material should be soaked before adding the seeds and placed under artificial light.
The favourite salad vegetable, the cucumber, positively thrives when grown in a hydroponic system. They require only moisture, nutrients and warmth for a rapid growth rate, with the hybrid varieties being the most successful, as they are resistant to disease. As a vine plant, they are ideal for vertical hydroponic systems.
Hydroponics is the fastest way of growing chillies, and you can get a high yield in a relatively small space. They work well in a static solution system, where the nutrient solution is aerated by the use of pumps and is changed once per week. For a more extensive set-up, with more plants, a continuous flow system can be used.
Green peppers typically grow the best using a hydroponics system, but you need to be careful to ensure the plants are not too close to the artificial lights, as they burn quickly. Care should also be taken with the temperature too, as extreme heat may cause the flowers to drop, thus not producing any peppers.
Which salad items do your family enjoy? Why not take this exciting opportunity to grow your own using this simple hydroponic system?