is a method of growing plants without the use of soil There are two main categories of hydroponic growing liquid and aggregate The liquid method uses no growing medium the plant is merely suspended over the nutrient solution so that its roots may absorb the needed elements The aggregate system has the plant supported by a sterile solid yet porous growing medium but again the roots are bathed with a nutrient solution to provide their nutritional needs All of the nutrients that the plant will require to grow are provided for in the liquid nutrient solution which is periodically provided to the plant by a variety of methods The light that all plants need in order to perform photosynthesis and to grow will be provided for in most instances by a man made lighting system
Many different varieties of plants can be grown using the hydroponic technique Some examples are lettuce herbs and tomatoes as well as seasonal flowering plant species The use of hydroponics in gardening as well as large scale crop growth can enable the grower to produce many types of plants out of their normal growing season Another attraction and use for hydroponic growing methods is that a person can have a garden in small spaces such as an apartment In addition a good source of natural sunlight is not required because the gardener will provide the plants light requirements
This form of growing plants is not only an interesting topic of study but also a viable method of producing many species of plants in either a small hobbyist garden or a large industrial crop producing system
Benefits of Hydroponics

There are a large number of benefits to be taken advantage of with the hydroponic method of growing In general the plants are going to be healthier grow faster grow more densely and in most instances be larger There are several different reasons for these wonderful effects on plants grown using the hydroponic method The plants will be healthier due to the lack of soil and its pests and parasites not to mention the lack of weeds Another positive aspect of no weeds is no weeding The gardener providing all of the plants required nutrients in the form of a liquid solution also is of importance in the health of the plants being grown The plants will not have to depend on the quality of the soil they are being grown in for their nutritional needs Plants in the garden will mature at a rapid rate because they do not have to compete for space and nutrients The same is true of the density or amount of plants which can be grown Again they do not have to compete with one another and their root systems do not have to spread out therefore the plants require much less space Because of this reduced need for space far more plants can be grown closely together The plants that grown will also tend to be larger for the same reasons mentioned previously
There are additional benefits to this method of gardening as well One example of these benefits is that hydroponic gardening is environmentally friendly To quote an article appearing in Mother Earth News hydroponics ultimately uses fewer chemicals and less water then conventional agriculture does38 Another great advantage is that you can grow plants out of their normal growing season This is of great help to those who love to cook and like to use fresh herbs for their dishes A world-renowned hotel the Waldorf-Astoria has taken advantage of this aspect of hydroponic gardening In The Edible Indoor Garden Peggy Hardingree states Since 1978 award-winning executive chef Arno Schmidt of the famed Waldorf-Astoria has been using modern hydroponics to keep his kitchen supplied with the fresh out-of-season herbs he needs to prepare the gourmet dishes served there 81 A few more benefits of hydroponics are that people in cities desert areas or other geographical locations where it is not suitable to grow crops can use this form of gardening to produce food stuffs The nutrient solution that is used to nourish the plants in a hydroponic garden can also be recycled as a good nutrient and water source for other house plants when it has been removed from the hydroponic system I am pleased to be able to say that in testing there was no difference in taste between conventionally grown and hydroponicaly grown plants In Mother Earth News it was reported that Mother first conducted a taste test of traditional vs hydroponically grown vegetables in 1976 and we have never found a significant flavor difference between the two 38
There are some interesting things that can be done with hydroponics Potato plants have been grown in outer space as an experiment to see how plants would fare in that setting The United States military uses this method of growing plants to provide fresh food stuffs to remote duty stations around the world and on submarines It has been stated in Future of Hydroponics It is a versatile technology appropriate for both developing countries and high-tech space stations 1
There are many diversified benefits of hydroponic gardening But to sum them up the gardener can control the environmental conditions like lighting water and nutrients producing a maximum crop output even in areas where there are little or no arable lands for farming while at the same time doing no damage to the environment itself

Potential Drawbacks to Hydroponic Gardening

There are a few downfalls when using the hydroponic growing method for either a small scale home garden or a large scale industrial cash crop venture The most difficulty that the home hobbyist should encounter is that it is not recommended that you grow plants where the root is the edible part of the plant This is due to the fact that in this growing method the root systems are quite a bit smaller than conventionally grown plants Therefore if one were to plant carrots in most instances the resulting crop would not be large enough to eat If you consider the larger scale farming venture then there are several things one would need to be cautious of and take into careful consideration There is likely to be a large amount of start up capitol required and the grower would need to have an in depth knowledge of both the crop or crops to be grown as well as hydroponic growing techniques In Overview of Hydroponics it is stated that The principle disadvantages of hydroponics relative to conventional open-field agriculture are the high costs of capital and energy inputs and the high degree of management skills required for successful production Capital costs may be especially excessive if the structures are artificially heated and cooled This is why appropriate crops are limited to those with high economic value 1 Even with these drawbacks hydroponics is a great way to have not only edibles out of season but provides a means of growing food for people who live in areas where it would not be normally possible

History of Hydroponics

Hydroponics can be traced back in its origins as far as the ancient hanging gardens of Biblical Babylon It is also believed that the Aztec had gardens which floated on rafts with the plant roots being allowed to dangle into the water for their nutrition In addition both the Chinese and some cultures living along the Nile River were known to have had gardens which floated on the waters surface An interesting fact brought out in History of Hydroponics shows just how far back in time this method of gardening was utilized The earliest food production in greenhouses was possibly the growing of off- season cucumbers under transparent stone for the Roman Emperor Tiberius during the first century 1
In more recent historical times beginning around the 1920s scientists became interested in began to experiment with and first used the term Hydroponics The experimentation continued sporadically throughout the 1920s and 30s but interest died out and the experiments were virtually abandoned This loss of interest was due mainly to the high costs involved and a large number of technical problems Approximately twenty years later there was a renewed interest in hydroponics but as in previous times the effort was not sustained This time it was due to the lack of pesticides available at the time as well as the cost factor again Beginning in the 1970s interest in hydroponics once again was renewed but this time the method has gained a foothold It is now considered to be a viable method for growing food stuffs in a large farm setting for cash crops in areas where arable land is not present as a means of providing plants out of their natural growing season as well as for the home hobbyist who just wants to grow fresh herbs vegetables or flowers Another reason for the revived interest in this method of growing is the ever increasing awareness that we must control and decrease the amount of pollution caused by fertilizers and their run off into the Earths water supplies This point is brought home in History of Hydroponics This is especially true in regions where there are environmental concerns in controlling any pollution of groundwater with nutrient wastes or soil sterilants 2 It is evident that hydroponics has been around for some time and that its value was known and utilized by the ancient peoples of our world This form of growing plants has a place not only in history but also in our world today Types of Systems
There are several types of hydroponic systems that a gardener may choose from On a small scale as in a home setting there are many choices In The Edible Garden Peggy Hardigree tells the reader that
hydroponic units are just coming on the market that bring
the cost of this type of gardening within reach of the
average home gardenerthe kits are being sold through major
chains such as Sears Roebuck Montgomery Ward and JC
Penny as well as at garden supply centers and major
supermarkets The kits are designed to retail for less
than 45 81
Most of the units for sale are relatively simple to set up and operate Many hydroponic systems use some form of media to support the plants and allow the roots to dangle below In a strict liquid system the plant would be supported in a plastic or wooden support ring or board Most growers prefer to use one of the aggregate systems which would utilize a form of media But whatever the choice of the gardener the basic techniques for growing the plants remain the same
The cost of operating one of these small units is very low Peggy Hardigree reports that The unit is said to cost only 6 cents per day to operate and it makes a gentle gurgling noise no louder than a coffee percolator The Edible Garden 81
Of course another option is to build a system Detailed instructions on building a hydroponic system are available both over the internet and in books on hydroponics In addition it would be possible to find most of the items needed right in your own home and those that are not available can be easily acquired at your local hardware and fish supply stores To construct a hydroponic system will likely take anywhere from one to two hours and require about a 50 expense It will be approximately another 30 for each florescent light tube that you purchase for your system Whether you build your own system or purchase a prepared kit hydroponic gardening can be a very enjoyable hobby
On a larger scale the systems are virtually the same but are set up in a greenhouse As stated above due to the high cost of start up and running a large hydroponic operation it is recommended that only high value cash crops be grown by this method

Types of Media

In hydroponics there are a variety of media that may be used in growing the plants In most cases gardeners will experiment with different types of media until finding one that works well for them
In both liquid and aeroponic gardens the plants being grown are suspended in a holder with the root system dangling below The roots of the plant are either soaked periodically or misted as in the aeroponic method with the nutrient solution
If the gardener chooses to use an aggregate type of system then a growing medium made up of a sterile inert material would be used to help support the plant Just as in a liquid or aeroponic system the root systems of the plants are bathed in the nutrient solution at periodic intervals
As noted in Growing Media There are numerous types of media used in aggregate hydroponic systems They include peat vermiculite or a combination of bothOther media such as coconut coir sand sawdust are also common in some regions of the world 2

Types of Plants and Their Requirements

Many diversified species of plants may be grown in a hydroponic garden As just a small example I offer the following suggestions Some fruits such as honeydew watermelon cantaloupe and strawberries do quite well Then there are the vegetables squash peas watercress tomatoes and salad greens in general do wonderfully in a hydroponic setting Flowers and herbs may also be grown Some examples of these would be basil oregano thyme and tarragon for the herbs and daisies primroses and violets representing the flowers Of course these are not all of the plants which could be grown in a hydroponic garden but just a short list to give a good impression of what could be done with even a relatively small garden
All plants require certain elements in order to grow successfully They need the proper nutrients and light to carry on photosynthesis which is the plants method of forming food for itself Most species of plants require roughly sixteen different elements in addition to light and water These elements range from Oxygen and Carbon Dioxide to Molybdenum The gardener may make his or her own nutrient solution if so desired but it is a rather tricky process and the person attempting to do so would need to be extremely knowledgeable in plant nutrition It is recommended that a pre-mixed solution be purchased in order to be absolutely sure that the plants being grown will receive all of their required nutrients in the proper amount There is one more method I would like to mention it is possible to make organic nutrient solution using a tea derived from a compost heap or manure pile
Each plant species has its own specific nutritional requirements and bearing this in mind the gardener should research each plant to be grown For example most leafy plants need more Nitrogen than fruit species would With this in mind it would be a good idea to grow species of plants together that have similar nutritional needs In addition the grower will want to carefully monitor the nutrient content of the solution as well as the pH levels on a regular basis The reason behind this monitoring is to be sure that the garden is receiving the proper amounts of nutrition at all times as well as maintaining the pH level between 5 and 6 If the pH is allowed to become either too high or too low the plants will be inhibited from absorbing the nutrients from the solution It is quite simple to check the pH levels all one would need is some pH testing paper which can be acquired at any local fish supply store The testing of the nutrient levels may be more difficult and if the gardener is not able to do so then it is recommended in Plant Nutrition that if no analysis is possible as will hold true for the majority of home gardeners then the nutrient solution should be completely changed every two weeks 6
If your pH levels do become either too high or too low there is a simple way to correct this As reported in Hydroponic Tutorial-Plants If your pH is too high correct with aspirin Two aspirin tablets per gallon of solution will lower a pH reading of 8 to about 6 A low pH can be corrected by adding baking soda 1 In addition if you find that your plants are exhibiting signs of nutritional deficiencies A quick fix for most of the deficiencies is to spray the leaves with an all-purpose foliar fertilizer Sorenson Relf Home Hydroponics 5 If you continue to have this type of problem it would be advised that the gardener change the nutrient solution
One thing which all hydroponic gardeners should remember is that both Sorenson and Relf state that the nutrient solution is the most important factor in the success or failure of a hydroponic system Home Hydroponics 2

Lighting

All plants regardless of their species need the same light A hydroponic garden is no different it must have one of two things either a good natural light source or the grower must provide adequate lighting
There are several routes which may be taken in regard to lighting the garden Gardeners fortunate enough to have a good sun light source are among a lucky few So for those of us who do not have adequate natural light here are just a few suggestions to solve the lighting dilemma A good type of artificial light is a HID high intensity discharge bulb These bulbs provide a super-growing atmosphere for your plants and the only real drawback with them is that they are rather costly Another good choice is to use fluorescent light bulbs Fluorescent bulbs come in both warm white and cool white and it is recommended that you use both types as warm provides much more of the red spectrum of light and cool provides the blue spectrum If both the warm and cool bulbs are utilized the garden will be provided a very good source of light These types of bulbs are also much less expensive than the HIDs and therefore more attractive to the home gardener who is working on a budget
Whichever type of lighting you would choose the grower should again research the light requirements for the plants to be grown

Pests and Diseases

It is most often believed that because a hydroponic system is free of soil it would also be free of pests and disease but this is not entirely true Yes a hydroponic system is soil free and this reduces the illness that effect many plants but the garden is still susceptible to some insects fungal bacterial and viral diseases
When dealing with insect pests the gardener should know that these annoying insects can multiply rapidly due to either having developed resistance to pesticides or the non-existence of natural environmental enemies that it would encounter in a traditional garden setting One remedy for these pests would be the deliberate introduction of natural enemies of pest insects particularly when used in association with horticultural practices Insects 1 If you do not wish to import insects into your garden there are alternatives The gardener could try one of the following two home made sprays One is a soap spray made primarily from garlic mineral oil oil-based soap and water The other is hot pepper spray which is made from garlic onion hot pepper cayenne and water Both of these remedies are reported to work very well in controlling pests and are for the most part natural
There is always the chance that the plants will acquire a fungus bacterial or viral type of illness as there are many different forms of these illnesses around If there are plants with fungus in your garden it is most important to remove and destroy the affected plants immediately so as to prevent the spread of the fungus to healthy plants To keep fungus at bay the area around the system should be kept clean and free of dirt or plant refuse
When dealing with either bacterial or viral types of illness the gardener should be sure to use only sterile media and equipment In addition the growers should be especially careful to wash their hands if they have touched or used any type of tobacco products The reason for this is that tobacco products are notorious for spreading a disease called Tobacco Mosiac Virus Most of these diseases have no cure and are highly contagious with the spread being very difficult to control Prevention is a far better means of dealing with these potential killers of a hydroponic garden than trying to cure them after they have already struck

Propagation

To begin a hydroponic gardening system seeds must be planted and tended until they are ready to be placed in the system There are several different methods of propagation but the following is the most common and probably the easiest method for the home hobbyist The seeds are generally started in a cube of sterile growing media The cubes containing the seeds are then placed in a tray of some sort and periodically watered The seed cubes may be either watered gently from above or by flooding and draining the bottom of the tray periodically When the seeds have grown enough they are then transferred to the actual garden Most plant species tend to follow roughly the same time frame and the following is a good guide for the home gardener to utilize As reported in Propagation the three stages of early development are germination post-emergence and transplant Germination should occur within one week of seeding post-emergence is generally 5 to 12 days and transplanting should be done between 12 and 14 days from seeding 2

Summary of Hydroponics

Hydroponics is not only an interesting topic of research but also a viable method of growing crops in non-arable areas and developing countries In addition it makes a wonderful hobby for all gardening lovers as well as a good source of out-of-season plants
With recent developments in the field of hydroponics it has become much more user friendly The fact that costs are coming down and the variety of kits both size and cost wise now available are very diversified helps the average gardener to be successful in their hydroponic adventure In addition Sorenson and Relf report that Information also is available through the Hydroponic Society of America PO Box 6067 Concord CA 94524 415 682-4193 Home Hydroponics 4
To close I would like to quote a statement made in Beginning Hydroponics by Richard E Nicholls Hydroponics is a method whose day is about to come 105

Works Cited

Bacterial and Viral University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhudroponicstomatoesviralhtm
Environmental Control Systems University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoessystemhtm
Fungal University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagArizonaeduhydroponictomatoesfungalhtm
Future of Hydroponics University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoesfuturehtm
Greenhouses University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoeshouseshtm
Growing Media University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoesmediahtm
Hardigree Peggy The Edible Indoor Garden New York St Martins Press Inc 1980
History of Hydroponics University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoeshistoryhtm
Hydroponic Tutorial-Lighting Growingedge date n pag Online Internet 28 Sept 1998 Available httpwwwgrowinedgecompageslightinghtml
Hydroponic Tutorial-Systems Growingedge date n pag Online Internet 28 Sept 1998 Available httpwwwgrowingedgecompageshydrohtml
Hydroponics the Revolution that Wasnt Mother Earth News Feb 1998 36
Hydroponic Tutorial-Media Growingedge date n pag Online Internet 28 Sept 1998 Available httpwwwgrowingedgecompageshmedhtml
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Hydroponics New Standard Encyclopedia 1983
Hydroponic Tutorial-Plants Growingedge date n pag Online Internet 28 Sept 1998 Available httpwwwgrowingedgecompagesplantshtml
Insects University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoesinsecthtm
Microsoft Encarta 98 Encyclopedia 1998 ed CD-ROM place publisher 1988
Nicholls Richard E Beginning Hydorponics Soilless Gardening A Beginners Guide to Growing Vegetables House Plants Flowers and Herbs Without Soil Philadelphia Running Press 1977
Overview of Hydroponics University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoesoverviewhtm
Plant Nutrition University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoesnutriohtm
Sorenson Ruth and Relf Diane Home Hydroponics Virginia Cooperative Extenstion 426-084 July 1996 n pag Online Internet 27 Sept 1998 Available httpwwwextvtedupubsenvirohort426-084426-084html
Tomato Timeline University of Arizona date n pag Online Internet 18 Oct 1998 Available httpagarizonaeduhydroponictomatoestimelinehtm