Hydroponics

This substitute for Mother Nature is challenging at best.

Hydroponic culture is justifiable only where plants must be grown without soil or for experimental and hobby purposes. Don't expect too much.

Hydroponics is a plant feeding method in which plant nutrients, in the form of soluble minerals, are supplied to the plant roots, in a solution. Very much the same way a plant picks up these nutrients from the soil. However. there's one big difference. In soil culture, the soil particles hold nutrients in reserve and feed them to the plants as the plants need them. In hydroponic culture, there is no reserve. The nutrient solution which bathes the roots in hydroponics is depleted of nutrients by the plants. The solution can be added to or changed to maintain the best concentrations for plant growth. Normally, it is changed weekly.

Hydroponic grower faces challenges…

Hydroponics does avoid several soil problems associated with soil texture, weeds and disease. But, the hydroponic grower faces other problems. He must substitute for Mother Nature and keep in balance all chemicals and physical conditions which surround the roots. If he doesn't, the plant can't get them anywhere else.

There are several forms of hydroponic culture. One is known as the NFT or Nutrient Film Technique. In this culture, the nutrient solution forms a thin water film which bathes the roots. Nutrients are pumped in at one end of a trough, trickle down through the roots, are collected, and pumped back through the bed.

Another form of hydroponic culture is called the sand culture method. In sand culture, a medium- to coarse-grained sand supports the roots in a trough or container. A complete nutrient solution is dripped or sprayed over the top to filter down through the roots. The solution may be collected, or just enough solution may be applied to wet the root zone thoroughly. This process is repeated several times a day as needed.

A third kind of hydroponic culture is called gravel culture. Here, pea-sized gravel supports and distributes the root system. This coarse gravel allows a nutrient solution to flow down a slope or to seep from a surface drip and filter down through the roots. When the nutrients flow back into the container, they can be recirculated; otherwise they are replenished weekly.

Hydroponic systems require quality pumps, timers and valves. The troughs or containers must be kept sterile. If a problem (such as disease) gets into the system, all plants will be infected as the solution is recirculated, if recirculation is the method you choose.

The nutrient solution is important.

Different plants require different solutions. A general solution, such as the modified Hoagland's Solution, is good for tomatoes, cucumbers and other fruiting crops.

For hobby purposes and for beginning hydroponic growers, it's best to start with a commercial solution and mix your own only after other culture problems have been solved. Mixing your own nutrient solution can be even more expensive than buying commercial formulations because many chemicals are expensive, especially when you buy them in small quantities.

Any hydroponic solution must contain essential plant nutrients such as, nitrogen, phosphorus, potassium, calcium, magnesium, iron, manganese, boron, zinc, copper and molybdenum. Lack of an element, or too little or too much of an element will mean inferior or dead plants. Commercial solutions will include directions about applying. Be aware that different environmental conditions, different varieties and different seasons will create different demands. Some demands can't be met by one particular blend or concentration of nutrients.

For more information on hydroponics contact your local County Extension Office.