Written by Juliette Scarfe
"Hydroponic" is a very general term used to describe the growing of plants without soil. "Hydroponic growing" simply means soilless growing. Since the prefix "hydro" means "water," many people think that hydroponic growing refers to growing in nothing but water. For the vast majority of hydroponically grown foods, however, water-only growing is not the case. Instead, hydroponically grown plants are raised in a variety of different media that substitute for soil. These media include sand, gravel, wood shavings, and vermiculite. Once the roots of the plants have been anchored in the soil substitute, they can be submerged in water that contains a carefully-blended set of nutrients matched to the needs of the plants. Plants grown hydroponically are typically raised in greenhouses, and the containers and equipment used to house and cultivate the plants have been made especially for that purpose. There are tens of thousands of acres of hydroponic production facilities in Israel, Holland, Australia, New Zealand, and England.
Hydroponics is not a new concept. Some believe the technique was used by the Babylonians to give Nebuchadnezzar’s Hanging Gardens their spot on the Seven Wonders list, and Allied forces in the Second World War used the process to supply troops with year-round fruit and veg.
Lettuce and tomatoes are the most common hydroponically grown vegetables, other hydroponic vegetables include broccoli, aubergine, summer squash, cauliflower, green beans, carrots, mushrooms, and sprouts. An increasing number of culinary herbs are also becoming available. Outside of the food world, flowers are the most common plants to be grown hydroponically.
If you can find certified organic, hydroponically grown vegetables, make those your first choice for a balanced, nutrient rich diet.
Advantages of Hydroponic Growing
Some of the reasons why hydroponics is being adapted around the world for food production are the following:
- No soil is needed
- The water stays in the system and can be reused - thus, lower water costs
- It is possible to control the nutrition levels in their entirety - thus, lower nutrition costs
- No nutrition pollution is released into the environment because of the controlled system
- Stable and high yields
- Pests and diseases are easier to get rid of than in soil because of the container's mobility
- It is easier to harvest
- No pesticide damage
Disadvantages of Hydroponic Growing
Without soil as a buffer, any failure to the hydroponic system leads to rapid plant death. Other disadvantages include pathogen attacks such as damp-off due to Verticillium wilt caused by the high moisture levels associated with hydroponics and over watering of soil based plants. Also, many hydroponic plants require different fertilizers and containment systems. To produce the mineral wool and the fertilizers that are needed to use this method, a large amount of energy is required.