What is hydroponics?

In nature, most plants use soil to grow. They get their nutrients from within the soil itself. However, if you can provide the nutrients another way, for many plants you don’t need soil at all. Soil-less growing, or hydroponics, is a technique where nutrients are added to water which is passed over the plant roots, which soak it up. Some plants have a stronger need for soil, such as root vegetables – these can’t easily be grown with hydroponics.

Exactly how you pass the water over the roots varies with different hydroponic techniques, ranging from letting the plant sit directly in water (Deep Water Culture), to spraying roots with a nutrient rich mist (Aeroponics). The Harvst H-Series Indoor Garden uses a “flood and drain” technique, which floods watering trays, pumps the fresh nutrient around the roots, and then drains it away again.

A seed will need something to sit in to germinate, and most plants need something to hold the roots, so hydroponic growing usually uses an inert “growing media” to replace the soil. It’s “inert”, because it contains no nutrients. An inert medium also is clean; there are no microbes, bugs or bacteria. The growing medium can be artificial, such as a rockwool or glass fibre plug, or natural such as a coir/coconut husk.

Plants also need air (carbon dioxide) for photosynthesis and growth … but it’s not just the plant’s leaves that need carbon dioxide, the roots need oxygen too. Soil has air spaces within it to let the oxygen in, and with a soil-less system we need to replicate this. It can either be done by letting the whole growing medium dry out, or by oxygenating the water, or both. The H-series “flood and drain” method lets the roots breathe between cycles. It also only floods the trays to partial depth of the growing medium, letting air roots do their job above the surface of the nutrient. Additionally, when the water runs back into the tank at the base, oxygen is introduced from the air. Read more about why roots need oxygen.

In a hydroponic system such as the Harvst H-Series, the nutrient solution drains back into the tank ready for re-use on the next irrigation cycle, making it more efficient than traditional methods of watering where much water is lost to evaporation or dispersion in the soil.

The nutrient concentration is important. Too strong or too weak, and the plants won’t like it. Different plants need different nutrient strengths, and also the demand can vary during the life cycle of a plant. Read more about nutrient concentration here.

Hydroponics is known for its ability to produce crops faster and with greater consistency than traditional soil-based gardening, and combined with a stable indoor environment, LED grow lights and climate control, the H-Series can help you produce food all year round.