Are Plants Grown Hydroponically Organic?

Growth Medium

• A hydroponic system does not use any soil, but the plants may be supported in an inert medium such as silica stones, rock wool or perlite, or a combination of these or others. It is important that the medium used for root and plant support be organic, which means that it has never been exposed to chemicals of any kind. Many of these mediums are organic materials that are heat-treated, making them excellent for use in an organic hydroponic system. If the support medium has been used with nonorganic methods, it should be replaced with fresh, unused medium for organic growing.

Packaged Nutrients

• Ready-to-use hydroponic nutrients are available from many different sources, needing only to be mixed with pure water to be used. If the nutrients are labeled as being organic, the plants grown with them will be organic as well, as long as other products, such as nonorganic nutrients or chemical pesticides, do not contaminate the system. A water-soluble organic fertilizer, when mixed with Epsom salts and water, makes a good general-purpose nutrient solution for growing organic hydroponic plants.

Compost Tea

• Organic hydroponic nutrient solution is easily made by using high-quality organic compost with water. It should then sit, or steep, for about 24 hours. The result of this is dark brown organic "compost tea," a nutrient-rich liquid filled with essential elements leached from the compost. Before using this tea in a hydroponic system, it should be well strained, so that no particles will clog the system. The main drawback of compost tea is that the nutrient levels are uncertain and can't be effectively controlled, so it won't work in all situations.

Worm Tea

• Similar to compost tea, worm tea is made from organic worm castings in the same way as compost tea. The difference is in the overall content of the tea. Worms chew through all kinds of things -- and as they go, they excrete droppings, called castings, that are rich in the nutrients that plants need, Worms also add nitrogen and beneficial bacteria, things that further benefit the plants. Like compost, worm castings are completely organic as long as the worms have eaten only organic foods.