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A method suited for urban kitchen gardens.

Gardeners and horticulturalists are used to getting grimy. They root around in the soil, applying fertilizers and pesticides. They plant, divide and re-plant. They do all this for the rewards of producing beautiful and nutritious plants to view and eat. But what if you could gain those values without coming into contact with any soil at all?

Soil-less Plant Culture

That's what hydroponics is all about. The name hydroponics suggests plants grown in water, and that method is used. But it really refers to any method of horticulture that doesn't use soil, usually in a highly artificial setting. So, it's sometimes called S/CEA or soil-less controlled environment agriculture.

Hydroponics offers many challenges, but has many benefits both to the plant and the gardener.

Water and nutrient control is more difficult. Light control is more important. pH adjustment is critical. In a soil-based garden, many of these factors are self-regulating, or mostly so. But in hydroponics, these need a little extra care from the gardener.

But hydroponics can actually yield larger fruits and larger output overall. More and larger plants can be produced in a smaller space, for a greater yield. That yield often comes with some efforts that are actually easier. Weeding, for example, is much less of an issue in the typical hydroponic setup. The medium makes it hard for the weeds to get started and they're easily out-competed or killed when they do.

To derive those benefits, the hydroponic setting has to be arranged, though.

One way to do that is by purchasing a complete hydroponic kit. Kits come with trays and tubing, nutrients, lights, air pumps and sometimes even seeds to get started. They're especially good for the novice because they package all the 'ingredients' needed to assemble a beginning hydroponic garden. Much of the knowledge needed to get started is incorporated in the kit.

But even a kit-housed hydroponic garden needs care. The right nutrients have to be fed to the plants. Even an automatic feeding system will need to be set up, filled and checked. Automatic watering systems, like drip irrigation or under-the-tray tubing will need to be built or arranged. Components have to be monitored for fungi and cleaned or sterilized.

Pest and disease control is required in hydroponic gardens, just as they are in 'ordinary' ones. Constant moisture provides a fertile environment for bacteria, mildew and other harmful organisms. White flies, aphids, spider mites, caterpillars and other common garden pests will still need to be dealt with.

Fortunately, there are numerous easy-to-use methods to tackle that problem. Insecticidal soaps, botanicals, fungicides and other compounds run the gamut from traditional 18th century methods which are still in wide use to chemicals fresh from the latest laboratory discoveries.

Hydroponics offers interesting variety, too. Some hydroponic gardeners prefer an all-water system. Trays that hold roots and solutions are fitted with supports from which strings can hold an upright plant. Other gardeners enjoy working with rockwool, perlite and other highly useful hydroponic media.

Some gardeners incorporate all the above in a convenient greenhouse. That allows them to control the light, air, water and other factors much more easily than other settings. Many greenhouses are modular and can be expanded as the garden 'grows'.

To get started using any method it's helpful to have some knowledge of elementary botany. Plants have unique needs and hydroponics builds on that base. Knowing what factors they require to flourish will get the hydroponic gardener started off in the right direction.

Get started on your hydroponics garden today. It's great fun!

What is hydroponics?

Hydroponics is the science and practice of growing plants without using soil. Water is the most common medium used instead. There are more technically accurate definitions, to be sure. But for the home gardener, hobbyist and occasional teacher that's what it comes down to.

But how is such a thing even possible? Don't plants need soil for nutrition, heat, support, water and all the other things they need to grow and reproduce? Not necessarily.

Plants definitely do need water. But they needn't get it from the soil, even though that's one of the most common methods. Even in nature, some plants grow in sand, gravel or even on the surface or underneath a body of water.

Plants need a certain amount of energy, in the form of sunlight and/or heat from their surroundings. But soil warmed by sunlight isn't the only way to get that. Direct sunlight still works on leaves, the same way it does for plants in soil. Leaving the upper part of a plant exposed to sunlight supported by a string atop a container will allow vital photosynthesis to occur. As with nearly anything in botany, there are exceptions. Some plants survive and reproduce with no light, though they still need some energy to drive biochemical reactions.

Most plants that interest the home gardener or hobbyist do require physical support. Planting them in soil is one common and effective way to achieve that. That's one of the reasons roots spread and stems are wind resistant. If they hadn't evolved that way, those types of plant wouldn't be here to discuss. But artificial aids, such as strings on supports, ice cream sticks glued to the top of a glass and dozens of other methods will work quite well.

One of the most important elements for a plant is without question proper nutrients. Nitrogen, phosphorus, potassium and a host of trace elements (zinc, copper, iron and others) are essential to plant growth. Absorbing those elements from the surrounding soil is, of course, one usual way of obtaining them. But, here again, nutrients can be fed to plants in a number of ways.

Immersing the roots in a container of water that is periodically fed a liquid nutrient solution is one popular technique. There are others. Some hydroponically grown plants are housed in an enclosure that retains moisture well. The roots are then sprayed often with a mister that douses the roots with a nutrient solution. This crosses into the gray area known as aeroponics.

Hydroponics can be used to grow a wide variety of plants: strawberries, tomatoes, lettuce and many non-fruit or vegetable plants, such as orchids. The list is long. Thousands of species can thrive without soil, provided they're cared for properly. That effort can be fun and instructive. It can also produce beautiful or nutritious plants without many of the drawbacks of soil-grown plants.