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Hydroponic Gardening

English: Rix Dobbs places a tomato plant in a ...

English: Rix Dobbs places a tomato plant in a nutrient film technique hydroponic tube he built in Durham, North Carolina. The PVC tube accomodates six pots. (Photo credit: Wikipedia)

Growing plants without soil is often called hydroponics. The name implies that the plants are grown in water containing dissolved nutrients. However, pure water culture is only one of the many methods employed. All of the other methods might simply be grouped as “soilless” culture, which would include sand culture, gravel culture, and culture utilizing other soil substitutes such as sawdust, wood shavings and vermiculite.

The Aztecs amazed the Spanish conquistadors with their floating gardens, and now 500 years later you can impress your friends and neighbors with yours. A floating hydroponic garden is easy to build and can provide a tremendous amount of nutritious vegetables for home use, and best of all, hydroponic systems avoid many pest problems commonly associated with the soil.

Ongoing research with plants such as tomato in floating systems indicate that larger plants may require more above-water rooting volume (more air-space) in order to produce successful yields. To produce more root mass above the water, you may want to test a system that uses two stacked styrofoam floats with holes drilled in the bottom one and all but a six-inch edge around the perimeter cut out of the top one. Fill the empty top float with perlite, vermiculite, or other hydroponic media and plant vegetables or flowers into it the same way you would plant a normal garden. Preliminary results show this method to be promising if starter fertilizer is used on the young plants until their roots reach the fertilized hydroponic solution below the floats.

Tomatoes and peppers are also challenging to grow in floating systems due to the high nutrient requirements for calcium. Blossom-end rot is caused by low calcium in the fruit. Supplemental calcium can be supplied in addition to the recipe above. These calcium products are available at most of the same suppliers that sell the net pots.

NASA researcher checking hydroponic onions wit...

NASA researcher checking hydroponic onions with Bibb lettuce to his left and radishes to the right (Photo credit: Wikipedia)


Benefits of Hydroponic Gardening

Critics of hydroponics claim that the method is too expensive and too complex. They also claim that it takes the fun out of gardening and is unaesthetic. The latter claim has some validity. Some community residents in Montreal were put off by the boxes of sterile, almost feathery growing medium. Many stressed that they were gardening for more than the potential vegetable yield, that they enjoyed working with dirt and compost. They wanted to learn about earth and they were quite willing to make do with the Intensified problems of container soil for the chance to work with that medium.

For people concerned with the economics and yields of urban gardening, though, hydroponics makes a great deal of sense. Though soil is cheaper to buy than perlite and vermiculite, the labor costs for the Montreal group in carting 100 cubic yards of earth to the roof were significant. These costs were slashed with the switch to the hydroponic medium which weighed only two percent the weight of dirt. Further, since container soil does leach so readily and does require repeated fertilization, the actual cost of fertilizer for container plants grown in soil is comparable to the cost for hydroponic nutrients. Two more considerations must be mentioned. First, since the hydroponic medium is so much lighter than dirt, a much larger surface area of the roof can be covered with containers without the fear of structural collapse. Also, since hydroponic roots do not need to grow as far In search of nourishment as do the roots of plants grown in soil, planting densities can be more intensive and higher yields can be achieved.

In terms of complexity, hydroponic gardening requires neither sophisticated equipment nor supervision. The technology is simple and easy to construct. The container must be slightly elevated at one end and have drainage holes at the opposite end. One-inch polyvinyl chloride pipes with holes drilled every three inches are laid about an inch under the medium and raised at both ends of the box. Smaller rubber hoses from the nutrient supply are inserted into the pipe at one end and the upward bend in the pipe at the other end stops the flow of the solution. A gravity system for controlling nutrient flow, composed of two five-gallon buckets elevated on boxes and standing two feet above the top of the growing container makes care for the hydroponic vegetables simple. The nutrients can be mixed directly into the water in the buckets and filling the buckets and adding the nutrients takes approximately five minutes of work each day. The hydroponic medium holds water so effectively that rare is further simplified: it is quite possible to skip a feeding for a day or two without causing any damage to the plants.

The experiments conducted in Montreal are important ones: the potential of organic hydroponics for producing both high yields and healthy produce on the rooftops of urban homes and businesses is significant. That the project was conducted in a low-income area and that the community residents have indeed taken over the garden project is also encouraging. Further work remains to be done: we hope to continue researching the methods and techniques of organic hydroponics in our newly completed rooftop greenhouse at the Institute for Local Self-Reliance in Washington, D.C. And we hope that more community groups try their luck with organic hydroponics … in Montreal, some people grew to love it.

via MotherEarthnews.com

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