Hydroponics Really Simple Plant Biology

Hydroponics is essentially a branch of horticulture or the practice of cultivating plants. Before one can cultivate well however, it is essential to have some knowledge of what plants need – and this is where botany comes in.

Some people are intimidated by the phrases ‘plant biology’ or ‘plant physiology’ and even the word botany. Certainly these sciences can be very complex and studying them is reserved for someone who is truly motivated or is a botanist by profession. However, even those who garden ‘by the seat of their pants’ can benefit from a small amount of such information, and it doesn’t have to be difficult to absorb.

Plants are living things but there is an important difference between plants and animals. Chief among those is a plant’s ability to absorb nutrients and generate what it needs – it does this by absorbing sunlight, which provides an energy source. At the same time, a plant can extract available chemical elements from the surrounding medium and transform them into food for itself.

Animals, on the other hand have to get their food from other sources, such as plants and other animals. Sunlight provides animals with warmth but not the energy to power their functions – however, there are exceptions as in all biology. Some extremely small organisms that are sometimes thought of as animals can perform plant-like activities and this makes them borderline cases.

The primary mechanism that most plants use to perform needed activities is photosynthesis which can be represented by a simple chemical equation:

6CO2 + 12H2O + light = C6H12O6 + 6O2 + 6H2O

Six molecules of carbon dioxide (6CO2) and 12 molecules of water (12H2O) combine by using energy provided by light. The chemical reaction produces glucose (C6H12O6), a type of sweetening agent. As with animals, the glucose is then later broken down to provide energy for various functions – a ’side benefit’ to the gardener is that six molecules of oxygen (6O2) and six of water (6H2O) are given off.

That relatively simple chemical reaction allows plants to be self-sufficient. They take in available energy, pull nutrients from their surroundings and produce their own energy and food. It would be great if humans could do the same! However, there is more to the plant’s life than energy production and food consumption. In order to perform those functions plants have to be sturdy and able to breathe.

In order to carry out essential processes, the plant needs a stable structure. Since hydroponics is soil-less, that support has to come from somewhere. Externally it is supplied by the medium which can be supporting trays, strings, or rockwool, etc. Internally, the plant’s own cells provide that support, using available elements.

Calcium, for example, plays a large role in forming a plant’s cell walls these eventually build up into tissues that form different types and enable features that stand up to gravity, wind and other forces.

Plants, like animals, perform a kind of respiration – breathing. Many of us are taught in elementary school that plants take in carbon dioxide and give off oxygen. That’s true. But they also consume oxygen. They simply give off more than they consume.

Plants don’t have lungs of course, but they do have stoma (pores or holes) that allow them to take in CO2 and oxygen and expel some of the O2 and this process is called cellular respiration which is essential to root growth.