Growing Vegetables without Soil
Hydroponic vegetables have been appearing in more restaurants and specialty markets lately. Unlike traditional vegetables, hydroponic vegetables are grown in water (not soil), often in greenhouses. An array of nutrients that plants normally get from soil, needed for proper growth, is added to the water. Hydroponic vegetable growers also often use gravel, sand, clay pellets, volcanic rock or another solid medium to support the plants.
Though the method has been used for centuries, the term hydroponics ("hydro" meaning water and "ponos" meaning labor) was coined about 80 years ago by a University of California, Berkeley scientist, who grew tomatoes, potatoes, corn and beans without soil. Today, you can also find hydroponic herbs, leafy greens, squash, eggplant, peppers and other vegetables, as well as watermelon, strawberries and other fruits.
Advantages and Disadvantages of Growing Hydroponic Vegetables
Growing plants hydroponically has advantages over traditional methods. Since no soil is involved, you don't need large tracts of land, nor do you get the potential problems from insects, fungi and bacteria in soil. There are no weeds and usually fewer insects, which means smaller amounts of pesticides are needed. (The USDA is in the process of considering standards for organic hydroponic operations.) Hydroponics also uses less water than conventional methods and doesn’t pollute natural waterways. Plants grow faster, crop yields are higher, and the produce tends to be locally distributed and fresher. What’s more, you can produce food anywhere, anytime.
But there are disadvantages, too. Certain organisms can still be a problem. And controlling the indoor environment of a greenhouse, including the lighting, requires a lot of energy. Because growers must monitor everything from temperature and humidity to pH and the amount of light the plants receive, hydroponics is also time- and labor-intensive. Not surprisingly, though prices vary widely, hydroponic produce can cost twice as much as field-grown vegetables.
Nutrition of Hydroponic Vegetables
Most studies find that hydroponic produce has pretty much the same nutritional profile as conventionally grown produce. As long as plants have adequate nutrients (whether from soil or water), light and air, they will grow properly. But keep in mind that nutrients and phytochemicals in fruits and vegetables can vary from batch to batch, no matter how they’re grown, depending on such factors as the crop variety, season, when the produce is harvested and how it’s handled and stored afterward.
BOTTOM LINE: There’s no downside to buying hydroponic produceexcept that it usually costs more. For the higher price, though, you are not necessarily getting more healthful produce, but produce that, in many ways, may be better for the environment.
Hydroponic Vegetables at Home
If you don’t have a backyard but want to grow vegetables, consider hydroponic gardening. You don’t need much space and can have homegrown vegetables year-round. There are many different systems available, which you can set up inside or on a deck or rooftop, for example. Today’s kits are lighter, simpler and more affordable than they used to be. Or you can build your own system with material from hardware and aquarium-supply stores. You can find resources for supplies onlinefor instance, at homeharvest.com/hydroponicsmain.htm.
Adapted from The University of California, Berkeley Wellness Letter (January 2012)