Some organic gardeners believe that hydroponic gardening can’t be organic because you don’t use soil. How can you have an organic garden without rich, loamy soil? Good soil is at the heart of organic gardening. Organic hydroponic gardening does exist, however, and has some advantages over conventional organic gardening.

Soil-less Gardening

Organic hydroponic gardening is organic gardening without the soil. Organic hydroponic gardening relies on water to provide the nutrients needed for plant growth. Organic hydroponic gardening still requires a growing medium; most plants won’t grow without something solid to put their roots into. The growing medium is not the source of nutrients, however; it’s as sterile as a chemically fertilized monoculture wheat field. The growing medium is simply a structure to root the plants into and to hold the nutrient-filled water.

Organic hydroponic gardening growing medium can be any organic material. Vermiculite and perilte are often used. (Be careful when handling vermiculite, as it is a source of asbestos.) Straw, cotton, plant fiber or any other organic material can be used.

The Secret is in the Water

Organic hydroponic gardening relies on dissolving substances in water to provide nutrients for the plants. Because it is organic, anything that goes into the water must be organic. Compost tea is frequently used in organic hydroponic gardening. It is made by soaking compost in water and straining out the solid material. The rich nutrients dissolve in the water and are used to feed the plants.

Manure tea is also used in hydroponic gardening. Manure tea can be a source of bacterial contamination of the produce, including contamination with lethal varieties of E. coli. Manure should be well-composted or sterilized before making manure tea. You make it the same way you make compost tea; by dissolving the manure in water and straining out the solid material.

Other organic additives that can be used are seaweed and fish emulsion. There are no special fertilizers because you continually circulate and refresh the nutrient mixture.

Special Uses

Organic hydroponic gardening has a niche in the organic gardening landscape. It fits anywhere that there is no soil available or the soil won’t support plant growth.

Organic hydroponic gardening is used to grow crops in parts of the world where the soil has been over-farmed and is too depleted to grow food. Organic hydroponic gardening is used in outer space living and will almost certainly be part of any attempt to colonize the moon or another planet. Organic hydroponic gardening is being used for urban gardens on rooftops. This enables urbanites to grow healthy food in wasted space. Rooftops can’t always support the weight of soil for traditional organic gardening.

Hydroponic gardening can be organic. You don’t get to play in the dirt, which is the part many organic gardeners love, but you do get to grow healthy, sustainable, organic food with organic hydroponic gardening.