Gardens that are grown in the same area year after year deplete the soil of valuable nutrients and food that your plants need to survive. Using additives, fertilizers, and additions to the soil, you can keep your garden area fresh and ready for any variety of plant that you want to grow in your garden. Cultivating your soil mixing the additives deep into the ground is going to give you that extra boost you need to have a fabulous garden that you are just going to love.

There are several types of organic matter that you can add to the soil that will boost the nutrients in the soil. Some of the organic matters that you can add to your soil are manure, leaves, grass clippings, straw, leftovers from your kitchen, peat moss, mulches, sawdust, barks, and wood chips. Organic material will decompose in your soil, raising the temperatures in the soil, keeping the soil active and adding to the foods that your plants need.

Gypsum is one source of calcium that many people forget about. Gypsum is found crushed in a bag, in drywall, in certain types of plaster and one of the most fascinating aspects of gypsum is that it can break up clay. If you have heavy soil this is one additive that will surely add to your garden over the years to come.

Lime is a additive that many types of soil need. Lime raises the pH level and testing your soil every three months in the summer and then every six months after adding lime will help you balance your soil well.

Greensand is slow release potassium that the soil loves. Potassium is a much-needed additive for many types of plants and you can find greensand from many marine deposits and old seabeds.

Sulfur will lower the pH levels of your soil, lowering the alkaline in the soil so that your non-alkaline loving plants can thrive. Sulfur is only used in very small portions as too much of it will deplete the soil of all the alkaline which is needed to balance the environment as well.
Some types of fertilizers do not give your soil all the added nutrients for plants to survive but at the same respect you are going to need to balance the additives that you put in the soil or you could end up with others problems in the soil that will require additional work.

Lighting Your Garden

There are four basic building blocks on which plant life is based:
     Light, Water , Nutrition, and Climate.
The most common factor that limits plant growth is the light source. Gardening outdoors, this obviously is not a problem; Mother Nature has seen to proper light balance and intensity for healthy plant growth. The responsibility for proper indoor lighting falls on the gardener. If your plants are not furnished enough light of the correct spectrum, they often will be mere shadows of what they could have been, if they grow at all. When you can't rely on Mother Nature to handle the lighting for you, the next best thing is a High-Intensity Discharge (HID) Metal Halide light system.

It is hard to compare HID lights with fluorescent tubes or incandescent light bulbs. Although they each create light from electricity, that's where the similarity ends. Fluorescent tubes emit a gentle, low temperature light in a very low wattage. Excellent for the first two weeks of most any plant's life, fluorescent lights simply do not provide the intensity of light required for most vegetables, flowers and ornamentals. Incandescent lights ('regular' light bulbs) are even worse for horticulture because they are very expensive to operate, put off as much heat as light, and do not offer the spectrums of light required for healthy plant growth. Even when incandescent light bulbs are altered with interior coatings to change their spectrum (like the "grow light" bulbs you see in the grocery store), they still do not come close to providing the kind of light a plant needs for robust, active growth. The only thing that will really grow and prosper under an incandescent grow bulb is your electric bill!

HID lighting systems represent the safest, most economical way of providing light for your plants. They are used all the time in parking lots, warehouses, baseball diamonds, football fields and other places where reliability and economy are a prime concern. Systems used for garden lighting are constructed differently, but the features of dependability and cheap operation remain the same. Two common types of HID lighting have been adapted for safe use in the garden and greenhouse, Metal Halide and High-Pressure Sodium.

Metal Halide light produces an intense light of a blue-white spectrum excellent for vegetative plant growth. Geraniums, marigolds, mums, zinnias, and violets all thrive under Metal Halide light, as do most vegetables. A plant grown under a halide light will often exhibit increased leaf growth, and strong stem and branch development. Roses grow hearty under metal halides, and seem to burst with buds before flowering time. A wonderful general purpose garden light.

High-Pressure Sodium Full Spectrum. (HPS) light puts off a complete full spectrum of light. These are the ideal light for all stages of growth. They have both blue and orange spectrums for vegetative and flowering growth. Due to these lamps having a full spectrum they are highly recommended. Perfect for any stage of growth, and excellent if you have plants at different life stages under one lamp. An example of a full spectrum bulb is the Sylvania Grolux.

High-Pressure Sodium. (HPS) light puts off an orange: shaded light which simulates the rich red hue of the autumn sun. Best as fruiting or flowering. lights, the HPS systems are often used In conjunction with metal halide for a complete balance of light spectrum in the garden. Flowers and vegetables finished off under HPS will show tighter, stouter blossoms with increased yields. HPS lights are commonly used in commercial greenhouses as starting lights and for supplemental light for off-season crops. Some types of plants respond particularly well to HPS lighting, such as the herbs dill and coriander.

Average Lumen Per Watt Output of Common Lamps

• 100 Watt Light Bulb - 17.5 Lumens per watt
• 400 Watt Fluorescent Tube - 22 lumens per watt
• 1000 Watt Metal Halide - 125 lumens per watt.
• 1000 Watt High Pressure Sodium - 140 lumens per watt

Keeping the grow room comfortable is accomplished by obtaining a balance of ventilation, air circulation, shading, humidity and heating. Providing the proper amount of each is the secret to a thriving greenhouse.

Ventilation

Overheating in the grow room can be mostly corrected with a nicely balanced ventilation system. Establishing a cross-flow of air utilizing low intake and high exhaust will exchange the hot air inside your greenhouse. Ideally, the air will be exchanged every 1-½ minutes. Whenever possible, try to position your intake to face the direction that your summer prevailing winds come from. This way, Mother Nature can work with you!An exhaust fan system works well in larger grow rooms and hot climates. The correct size of vent system depends on the volume of air inside your grow room, not your plants or climate zone. A thermostat turns on the system at the temperature that you select. The fan expels hot air and fresh, cool air is drawn in through the shutters.Roof vents and side vents work well in smaller grow rooms in moderate climates. (Roof vents should not be used in conjunction with a fan vent system. The exhaust fan would pull in air through the roof vents, not from the lower intake shutters.

The wonderful smell of a forest floor is the smell of humus, or completely rotted plants and animals. Decomposed organic matter is compost. The original organic matter is no longer discernable and you have rich, black, sweet-smelling, crumbly, soil-like substance.

Composting your organic wastes not only keeps them out of the landfills, but when applied back into your lawn or garden, it also increases the health of your soil. Nutrients were stored in the decaying organic matter. Compost holds these nutrients in a form that is easily absorbed by plant roots.

Use of Natural Process

Home composters use nature's process to reduce yard trimmings and organic matter to compost. After a plant or animal dies, bacteria go to work to decompose the remains. Bacteria initiate decomposition of plants. Various types of bacteria thrive in environments with specific conditions. In order to speed the composting process, we manipulate the environment in the compost pile to attract bacteria which will reduce the pile with greatest speed.

The environmental factors we will manipulate are:

• Air
• Moisture
• Carbon and Nitrogen Materials (Food for Microorganisms)
• Mass
• Time

Environment as Home to Bacteria

All living organisms require air, moisture, and a mix of carbon and nitrogen food. In the compost pile, we strive to have levels of moisture, air, carbon and nitrogen that will attract three types of bacteria: first, psychrophilic; second, mesophyllic; and third, thermophilic.

The psychrophylic bacteria join the pile when the temperature of the pile is between 0 degrees F to 55 degrees F. This is the pile temperature when you first build it. The psychrophylic bacteria begin to decompose the pile by breaking down the particles. If there is enough air, moisture, and food in a pile in this temperature range, the phychrophilic bacteria will be very happy. When bacteria are happy, they eat and reproduce. Reproduction occurs by literally splitting themselves in half down the middle and becoming two bacteria. Bacteria reproduce at amazing speed. One gram of Escherichia coli in favorable conditions takes only three hours to become a pound. This amazing rate of reproduction, in addition to the eating frenzy which occurs, builds heat. If the compost pile is a minimum of 3 x 3 x 3 feet, the center of the pile will retain the heat that is generated. If the pile is smaller, the heat will escape into the air and the pile remains cool. Mass is one of the variables we control by building piles of at least 1 cubic yard.

As the heat in the center builds to between 50 and 100 degrees F, the mesophyllic bacteria are attracted to the pile. If the pile is between 70 and 90 degrees F, the mesophyllic bacteria will eat and reproduce at their peak rate. The result is heat, and the center of the compost pile is raised further.

If the heat of the pile reaches 104 to 170 degrees F, the thermophilic bacteria will begin their work on the pile. To get compost quickly, you must attract this type of fast-working bacteria. As the food and water source begin to dwindle in the hot center of the pile, the thermophilic bacteria slow down their activity. When your pile starts to cool off, you must turn it (i.e., stir up the contents) so that the middle of the pile has the moisture, air, and food to rekindle activity of the thermophilic bacteria and keep the pile hot. Every time the pile starts to cool off, turn again. (This is for the fastest compost, of course. If you can wait, don't turn the pile and let the mesophyllic work on your pile.)

Eventually, the pile will not be able to retain enough heat to remain over 100 degrees F. The mesophyllics will take over at the center (they have been operating outside the center all along), and other microorganisms, fungi, protozoans and other invertebrates will turn out to assist. As the process continues, they will be joined by other macroorganisms, including centipedes, millipedes, beetles, and earthworms.

Given enough time, all organic matter will decompose. In a forest, you will find layers which have been deposited on the ground over a period of years, in various stages of decomposition. Tips, instructions, and information on this site are intended to speed up this process so that you can more quickly create nutrient-rich compost for your garden.

Hydroponic Growing Mediums:

In a traditional garden, plant roots are in the soil. They support the plant and search for food and water. In hydroponics, we often use a growing medium in place of soil. The roots of a hydroponic plant do not work as hard as those of a plant grown in soil because their needs are readily met by the nutrient solution we feed them.

Ideal mediums are chemically inert, porous, clean and able to drain freely.

Many materials have been used as hydroponic growing mediums. These include: vermiculite, saw dust, sand, peat moss and, more recently, rockwool, perlite and expanded clay pebbles. Today's popular growing mediums, perlite, rockwool and expanded clay pebbles are described below.

Rockwool
Rockwool is derived from basalt rock. It too is heated to high temperatures but then is spun into fibers resembling insulation. These fibers are spun into cubes and slabs for hydroponic production. The cubes are commonly used for plant propagation and the slabs are used similarly to the perlite grow bags. A plant is set onto the rockwool slab and grown there. The plant roots grow down into the slab. Rockwool slabs usually hold 3or 4 long term plants.

Perlite
Perlite is derived from volcanic rock which has been heated to extremely high temperatures. It then explodes like popcorn, resulting in the porous, white medium we use in hydroponics. Perlite can be used loose, in pots or bagged in thin plastics sleeves, referred to as "grow bags" because the plants are grown right in the bags. Plants in perlite grow bags are usually set up on a drip feed system. Perlite grow bags usually hold 3 or 4 long-term plants. Perlite is also used in many commercial potting soil mixes.

Expanded Clay Pebbles
Many hobby hydroponic gardeners use expanded clay pebbles for their growing medium. Expanded clay pebbles have a neutral pH and excellent capillary action. Often Ebb and Flow systems use expanded clay pebbles in the grow.

Plant Needs

Like humans and animals, plants have very specific nutritional and environmental needs that must be met in order for the plant to grow and develop. Both humans and plans must consume a balanced diet and need protection from harsh environments. Plants all over the world have adapted to specific environments. A tomato plant, for instance, is a tropical plant and thrives in average daytime temperature of 80 F and nighttime temperature of 60 F. When grown in temperatures outside these parameters a tomato plant may survive, but not thrive and, if the temperatures are too extreme, the tomato plant will die.

Individual species of plants have very specific nutritional needs that must to be met. These needs may vary through-out the stages of the plant's growth.

For instance, a tomato plant needs more nitrogen during the vegetative growth stages and less nitrogen during the fruiting stages.

As a compromise to various needs and stages of growth, hydroponic solutions can generally be modified to be suitable for the majority of plants. For best results, it is a good idea to plant crops with similar needs together so the compromise in minimal.

In the soil, organic materials are broken down to release minerals and nutrients. They can then be dissolved in water, taken up by the roots and passed through the stem into the leaves. In hydroponics we provide the minerals a plant needs in a water-soluble form, ready to be taken up by the plant roots. We are therefore able to provide a very exact diet for our plants in the most usable form.

The more precisely a plant's needs are met, the more vigorous its growth will be. When you observe a lush, healthy plant, you can be sure that most or all of it's environmental and nutritional requirements are being met.

Introduction to Hydroponics

Hydroponics by definition, means 'water-working." In practical use, it means growing plants in a water and nutrient solution, without soil. Hydroponics allows a gardener to grow plants in a more efficient and productive manner with less labor and time required.

The science of hydroponics proves that soil isn't required for plant growth but the elements, minerals and nutrients that soil contains are. Soil is simply the holder of the nutrients, a place where the plant roots traditionally live and a base of support for the plant structure.

In hydroponics you provide the exact nutrients your plants need, so they can develop and grow. The nutrients are fed directly at the root base, never stressing the plant due to lack of nutrients or water.

Virtually any plant will grow hydroponically, but some will do better than others. Hydroponics growing is ideal for fruit bearing crops such as tomatoes, cucumbers and peppers, leafy crops, like lettuce and herbs and flowing plants. Most hobby hydroponic gardeners plant crops similar to what they would grow in a soil garden

Most commercial hydroponic growers combine hydroponic technology with a controlled environment to achieve the highest quality produce. Within a green- house structure you can control the ambient temperature, humidity and light levels allowing you to grow on a year- round basis.

Advantages of Hydroponic Growing
There are many advantages of hydroponic growing. These include:

Most hobby hydroponics gardens are less work than soil gardens because you do not have soil to till or weeds to pull.

By eliminating the soil in a garden, you eliminate all soil borne disease

A hydroponic garden uses a fraction of the water that a soil garden does because no water is wasted or consumed by weeds.

In hydroponics, plant spacing can be intensive, allowing you to grow more plants in a given space than soil grown produce.

A small hydroponics garden can be set up almost anywhere.

By providing the exact nutrients your plants need, they will grow more rapidly and produce bigger yields.

In studies it has been proven that hydroponic produce is higher in nutritional value than field grown crops.

Hydroponics produce generally tastes better than field-grown produce.

If you are growing indoors or in a greenhouse, you can grow your hydroponic plants on a year-round basis.

Factors to Consider

When growing plants in a hydroponic garden, we must consider these factors:

the amount of water the plants need; proper drainage of growing medium
the optimum temperature and light for the plant
fresh air
shelter and support
pest and disease control
the water-soluble minerals the plant needs
the proper pH of the nutrient solution
Water:

As with all plant needs, the amount of water required depends on the species and the needs of that particular plant. A plant that suffers from lack of water will extend a huge, but not very effective root system, and will develop a very small plant above the ground. Many roots are sent out in search of water and when an inadequate amount is found, the plant will not grow to its potential. In the other extreme, if a plant is over watered the roots can drown because they are not receiving the proper amount of fresh oxygen. This makes proper drainage of a hydroponic growing medium crucial to your plant's health. The last consideration concerning the water you feed your plants is purity. In a hydroponic garden, you should use as pure of water as possible. Water that has possible toxic contaminants or salt build ups may stunt or kill your plants.

Temperature and Light
The ideal temperature depends on the crops you choose to grow. Most of the common garden crops, such as tomatoes, cucumbers, lettuce, beans and peas will do well with an average daytime temperature of 78 F and an average nighttime temperature of 64 F. Winter vegetables, such as cabbage, brussel sprouts and broccoli should be grown in slightly cooler temperatures.

A minimum/maximum thermometer will allow you to track the low and high temperatures in your growing environment. This is important for monitoring overall progress of your hydroponic garden and diagnosing plant growth problems.

For optimum production, heating the root zone is important. For most garden crops 72 F is the ideal root zone temperature. Some growers achieve a heated root area by using heated grow mats placed under the growing medium. Another option is to heat your nutrient solution to the desired temperature and then when your system feeds the plants, the roots are bathed in warm water.

Primary Hydroponic Growing Methods

Four Primary Hydroponic Growing Methods:

In a soil garden, plants are rooted in the soil and draw nutrients from it. In hydroponics, a nutrient rich solution is fed directly to the plant roots. In some hydroponic growing systems an inert growing medium, such as perlite, rockwool or expanded clay pebbles is used in place of soil. These growing mediums are porous and absorb the nutrient solution, allowing the plants to use it as needed.

In other hydroponic systems, like the NFT system, no growing medium is used and the plant roots are suspended in a grow channel.

The four most common methods of hydroponic gardening include:

Nutrient Film Technique (NFT)
Passive System
Ebb and Flow
Drip Method

NFT
With the Nutrient Film Technique (also known as NFT) the plants are grown in channels which the nutrient solution is pumped through. The plant roots are flooded by the nutrient solution as it passes by. Ideally, the bottom of the roots are exposed to the nutrient solution, while the top of the roots are exposed to air. Most NFT systems are fed on a very frequent timed cycle. For instance, 10 minutes of nutrient solution flow, followed by 5 minutes of nutrient solution drain. Since the plant roots are not in a growing medium, it is crucial that they are flushed often to keep them moist.

NFT is ideal for lettuces, leafy crops and herbs, all of which are short term crops. Larger NFT channels can be used long term crops as long as some form of plant support is provided..

Passive
The advantage of a Passive hydroponic garden is its low maintenance. A Passive system does not use pumps or timers to flood the root zone. The roots usually dangle in the nutrient solution and draw what they need from it. A Passive system is generally slower growing and not as intensive as the other systems discussed.

Because there is no water movement, passive systems will often have low oxygen levels. this can be remedied by adding a small air pump that pumps air into the nutrient reservoir.

The Ebb and Flow
The Ebb and Flow (also know as flood and drain) method of hydroponic gardening simply allows all the plants in the garden to be fed the same amount of nutrient solution at the same time.

The plant grow bed, which contains plant pots filled with a growing medium, is flooded with the nutrient solution for a set period of time and then allowed to drain for a set period of time. This allows the growing medium and plant roots to stay moist while bringing fresh oxygen to the root base each time the nutrient solution drains away.

Most Ebb and Flow systems will flood the grow bed for 10 or 15 minutes of every hour or two In an Ebb and Flow system, the plant roots are most commonly grown in a medium of perlite, rockwool or expanded clay pebbles.An Ebb and Flow system, popular with many home hydroponic gardeners, is ideal for growing a broad variety of crops since both long and short term crops do well in this system.

Drip
In a Drip system, the nutrient solution is delivered to the plants through drip emitters on a timed system. The timed cycle flushes the growing medium, providing the plants with fresh nutrients, water and oxygen as the emitter is dripping. The emitters are usually scheduled to run for approximately 5-10 minutes of every hour. In a drip system, the plant roots are most commonly grown in a medium of perlite, grow rocks or rockwool. The drip system is often used in commercial hydroponic facilities that grow long term crops like tomatoes, cucumbers and peppers.

Hydroponics: Past, Present, Future

When you are first introduced to hydroponics, you may assume that is a new concept. That assumption is incorrect. Although hydroponics has become very high-tech, it is at least as old as the pyramids.

The First Hydroponics Gardens... 600 BC
Plants have grown in our lakes and oceans from the beginning of time but, as a farming practice, many believe it started in the ancient city of Babylon. The Hanging Gardens of Babylon are believed to be the first successful attempts to grow plants hydroponically.

Along the Nile, hieroglyphic records dating back several hundred years BC describe the growing of plants in water, without soil.

Before the time of Aristotle, Theophrastus (327-287 BC) undertook various experiments in crop nutrition. Botanical studies by Dioscorides date back to the first century A.D.

The Floating Gardens of the Aztecs
In the 11th century, The Aztecs of Central America, a nomadic tribe that was driven onto the marshy shore of Lake Tenochtitlan in the central valley of what is now Mexico, practiced hydroponic growing methods out of necessity. Without land to grow plants, they were forced to learn other ways of producing crops. Being a very ingenuous people, they built rafts out of rushes and reeds, lashing the stalks together with roots. They dredged up soil from the shallow bottom of the lake and piled it onto the rafts.

Chinampas
Floating Rafts of the Aztecs
Soil was taken from the bottom of Lake Tenochtitlan and placed on the rafts which were made of reeds, rushes and weeds. The soil was rich in organic debris which provided nutrients to the plants. Plants were placed on top of the soil. The plant roots grew through the soil and down into the water be- low. Some of the Chinampas were as long as 200 feet, growing vegetables, flowers.

Because the soil came from the bottom of the lake, it was rich in organic debris that held nutrients necessary for plant growth. Vegetables, flowers and even trees were grown on these floating rafts, called Chinampas. The plant roots would grow through the mats and down into the water.

The Chinampas were sometimes joined together to form floating islands as large as 200 feet long. Some Chinampas had a resident gardener who harvested and sold the vegetables and flowers on the raft.

As the Aztec village became huge, so did their floating gardens. During the invasion of the Aztec villages by the Spaniards in the 16th century. these floating gardens were witnessed and documented. Such an innovative, yet productive plant growing system must have shocked the invaders.

Use of the Chinampas, or floating gardens, continued into the 19th century and some remnants can still be seen in Mexico today.

Other Examples of Hydroponics in History
Another example of hydroponics was described by Marco Polo in his famous journals. As he traveled through China (c1275 -c1292), he wrote of the floating gardens of the Chinese.

1600's: Early Scientific Experiments in Hydroponics:
In 1600, Belgian Jan van Helmont derived that plants obtain substances for growth from water by planting as lb willow shoot in a tube containing 200 pounds of dried soil. After 5 years of regular watering with rainwater, he found the willow shoot increased in weight by 160 lbs, but the soil lost less than 2 ounces. What he did not realize was that plants also require carbon dioxide and oxygen from the air.

In 1699, plants were grown in water containing various amounts of soil by John Woodward. a fellow of the Royal Society of England. Mr. Woodward found that the greatest growth occurred in the water which contained the most soil. He concluded that plant growth was a result of certain substances and minerals in the water, derived from the soil. This mixture of water and soil was the first man-made hydroponic nutrient solution.

European plant physiologists established many things in the decades that followed Woodward's research. They proved that water is absorbed by plant roots, that it passes through the plants stem system and that it escapes into the air through pores in the leaves. They also showed that plant roots take up minerals from either soil or water and that leaves draw carbon dioxide from the air. They also demonstrated that plant roots take up oxygen.

The determination of precisely what it was that the plants were taking up was delayed until the modern theory of chemistry made great advances in the seventeenth and eighteenth centuries.

In 1792 English scientist Joseph Priestly discovered that plants placed in a chamber filled with carbon dioxide will gradually absorb the carbon dioxide and give off oxygen. Two years later, Jean Ingen-Housz demonstrated that plants in a chamber filled with carbon dioxide could replace the gas with oxygen within several hours if the chamber was placed in sunlight. It was a fact that the plant was responsible for this transformation. eluding to the first concept of photosynthesis.

1800's -1920's: Great Scientific Breakthroughs
Between the early 1800's and the 1920's, phenomenal discoveries and developments were achieved in laboratory studies of plant physiology and plant nutrition. In 1925. the greenhouse industry expressed interested in the newly acquired knowledge in "Nutriculture," as it was called at that time. Between 1925- 1935, extensive development took place in converting the laboratory techniques of nutriculture to large-scale crop production.

1930's: Dr. William F Gericke
In the late 1920's and early 1930's, Dr. William F. Gericke of the University of California at Berkeley, focused his research on growing practical crops for large scale commercial applications. During this time, he coined the term, "hydroponics", which was derived from the Greek words, hydro (meaning water) and ponos (meaning labor) literally "water-working." His work and research is considered the basis for all forms of hydroponic growing even though it was primarily limited to water culture without the use of a growing medium.

Dr. Gericke was photographed with tomato plants that exceeded 25 ft. in length. These photographs appeared in newspapers throughout the country and created both excitement and skepticism in the general public. Promoters and equipment manufacturers proceeded to cash in on the media-hype by selling useless equipment and materials promoted to grow goliath plants.

In reality, Dr. Gericke's newly developed hydroponic growing system was far too scientific and complex for most potential commercial growers.

1940's: Hydroponic Technology Used in W W II to Feed Troops
During the late 1940's, a more practical hydroponic method was developed by Robert B. and Alice P. Withrow, working at Purdue University. Their system alternately flooded and drained a container holding gravel and the plant roots. This provided the plants with the optimum amount of both nutrient solution and air.

During World War II the shipping of fresh vegetables overseas was not practical and remote islands where troops were stationed were not a place where they could be grown in the soil. Hydroponic technology was tested as a viable source for fresh vegetables during this time.

In 1945, the US Air Force built one of the first large hydroponic farms on Ascension Island in the South Atlantic, followed by additional hydroponic farms on the islands of Iwo Jima and Okinawa in the Pacific, using crushed volcanic rock as the growing medium and, on Wake Island west of Hawaii, using gravel as the growing medium. These hydroponic farms helped fill the need for a supply of fresh vegetables for troops stationed in these areas.

During this time, large hydroponic facilities were established in Habbaniya, Iraq and Bahrain in the Persian Gulf, to support troops stationed in those areas near large oil reserves.

The American Army and Royal Air Force built hydroponic units at various military bases to help feed troops. In 1952, the US Army's special hydroponics branch grew over 8,000,000 lbs. of fresh produce for military demand. Also established at this time was one of the world's largest hydroponic farms in Chofu, Japan, consisting of 22 hectares.

Following the success of hydroponics in W W II, several large commercial hydroponic farms were built in the US, most of which were in Florida. Due to poor construction and management, many of these farms were unsuccessful.

1945-1960's: Use of Hydroponic Culture Expands
Because no soil was needed and, with proper management optimum results could be had, the excitement over hydroponics continued and its use expanded throughout the world, specifically in Holland, Spain, France, England Germany, Sweden, the USSR and Israel. Areas with little rainfall, poor or no soil and difficult access were ideal for hydroponic culture.

Between 1945- 1960's both individuals and garden equipment manufacturers were designing hydroponics units for home use. Some were quite efficient while others failed due to poor growing media, unsuitable construction materials, poor construction and improper environmental control.

Even with many failures, the idea of creating the ultimate growing system intrigued many and research and design continued in the field of hydroponic culture.

1970-80's: New Technology Brings Hydroponic Production into Mainstream
In the mid 1970' s another media blitz about the miracles achieved with hydroponic technology hit the United States. Again, hydroponics was considered a get rich quick scheme and many hopeful investors lost big money on failed hydroponic farms.

Even though the potential of hydroponic culture is incredible, commercial hydroponics in the US was held back until hydroponic systems that were economical to build and relatively easy to operate, became available in the marketplace. With the advent of high-tech plastics and simpler system design, this came about in the late 1970's. The energy saving poly greenhouse covers, the PVC (or similar) pipe used in the feed systems, the nutrient injector pumps and reservoir tanks are all made of types of plastic that weren't available prior to the 1970' s.

As both small and large hydroponic farms were established in the late 1970's, it was proven that, with proper management, hydroponic culture could produce premium produce and be a profitable venture. As hydroponics attracted more growers, complete plant nutrient formulas and hydroponic greenhouse systems were being marketed. Environmental control systems were being developed to help to growers provide the ideal plant environment in addition to the ideal plant diet.

Drip irrigation is the most efficient method of irrigating. While sprinkler systems are around 75-85% efficient, drip systems typically are 90% or higher. What that means is much less wasted water! For this reason drip is the preferred method of irrigation in the desert regions of the United States. But drip irrigation has other benefits which make it useful almost anywhere. It is easy to install, easy to design, can be very inexpensive, and can reduce disease problems associated with high levels of moisture on some plants. If you want to grow a rain forest, however, drip might not be the best choice!

Drip irrigation (sometimes called trickle irrigation) works by applying water slowly, directly to the soil. The high efficiency of drip irrigation results from two primary factors. The first is that the water soaks into the soil before it can evaporate or run off. The second is that the water is only applied where it is needed, (at the plant's roots) rather than sprayed everywhere. While drip systems are simple and pretty forgiving of errors in design and installation, there are some guidelines that if followed, will make for a much better drip system.

Just as we zone plants in the landscape according to their different water needs, irrigation systems should be zoned so that plants with different water needs are irrigated separately. Turfgrass, for example, should be watered separately from shrubs and flowers.
Using irrigation water efficiently also requires proper selection of irrigation methods for the plants and for each area of the landscape.
Trees and shrubs in the low-water-use zone need supplemental water only during establishment or the first growing season (first 8 to 10 weeks after transplanting), whereas plants in moderate-water-use zones require water only during periods of limited rainfall when they show signs of stress. For these plants, a temporary system such as a soaker hose or hand watering may be all that is required. On the other hand, high-water-use zones require frequent water- ing and may warrant a permanent system with automatic controls. Whenever possible, use highly efficient watering techniques, such as drip irrigation.

Drip Irrigation

Drip irrigation, also called trickle or micro-irrigation, applies water slowly and directly to the roots of plants through small flexible pipes and flow control devices called emitters. Drip irrigation uses 30 to 50 percent less water than sprinkler irrigation and usually costs less to install. Since water is applied directly to the root zone, evaporation and runoff are minimized.
Drip irrigation is recommended for use on trees, shrubs, and flowers in the high- and moderate-water-use zones of the landscape to maximize efficiency. Several types of drip irrigation systems can be adapted to suit a variety of applications, from watering individual trees and shrubs to beds of annuals, herbaceous perennials, ground covers, or mixed borders.

Parts of a Drip System

In a drip system, water is distributed to the plants through small, flexible 3/8- to 3/4-inch-diameter plastic pipes and emitters or by perforated or porous pipe.

Emitters may be purchased separately from the tubing and placed in the line wherever watering is desired. Another option is to purchase drip tubing with emitters already installed at the factory, usually spaced 12 to 24 inches apart. Most emitters will discharge water at a rate of 1/2, 1, or 2 gallons per hour at a pressure of about 20 pounds per square inch (psi).

Perforated or porous pipe discharges water along its entire length to wet a continuous strip. By spacing pipes 12 to 18 inches apart, it is possible to wet a solid area. It is a good system for closely spaced plantings of annuals, herbaceous perennials, or ground covers.
Most drip systems include polyvinylchloride (PVC) pipe for the main lines and polyethylene (PE) tubing for distribution lines. Polyethylene tubing is flexible, easy to cut, and can be connected without glue or clamps. Emitters are installed by punching a hole in the polyethylene tubing and snapping the emitters into place.

A drip system must have a main valve to turn it on and off. This may be an automatic electric valve connected to a controller or a manual gate valve. You can also connect the drip lines directly to an outside faucet. However, when connecting the system directly to the faucet, use an automated timer to turn the system off after a preset length of time. Otherwise, you may forget and leave the system on for several days.

Two other necessary components of a drip system are a filter and a pressure regulator. A drip system uses small passageways to control the rate of water application so even tiny particles suspended in the water may cause clogging. To prevent clogging, use a screen filter with a 150- to 200-mesh screen. These components are usually installed below ground in a valve box.

Most drip systems are designed to operate at a pressure of about 20 psi. In comparison, household water pressure typically ranges from 40 to 100 psi. A pressure regulator installed immediately after the filter in the main irrigation line reduces the pressure in the line and helps to ensure efficient system operation.

Lighting Your Garden

There are four basic building blocks on which plant life is based:
     Light, Water , Nutrition, and Climate.
The most common factor that limits plant growth is the light source. Gardening outdoors, this obviously is not a problem; Mother Nature has seen to proper light balance and intensity for healthy plant growth. The responsibility for proper indoor lighting falls on the gardener. If your plants are not furnished enough light of the correct spectrum, they often will be mere shadows of what they could have been, if they grow at all. When you can't rely on Mother Nature to handle the lighting for you, the next best thing is a High-Intensity Discharge (HID) Metal Halide light system.

It is hard to compare HID lights with fluorescent tubes or incandescent light bulbs. Although they each create light from electricity, that's where the similarity ends. Fluorescent tubes emit a gentle, low temperature light in a very low wattage. Excellent for the first two weeks of most any plant's life, fluorescent lights simply do not provide the intensity of light required for most vegetables, flowers and ornamentals. Incandescent lights ('regular' light bulbs) are even worse for horticulture because they are very expensive to operate, put off as much heat as light, and do not offer the spectrums of light required for healthy plant growth. Even when incandescent light bulbs are altered with interior coatings to change their spectrum (like the "grow light" bulbs you see in the grocery store), they still do not come close to providing the kind of light a plant needs for robust, active growth. The only thing that will really grow and prosper under an incandescent grow bulb is your electric bill!

HID lighting systems represent the safest, most economical way of providing light for your plants. They are used all the time in parking lots, warehouses, baseball diamonds, football fields and other places where reliability and economy are a prime concern. Systems used for garden lighting are constructed differently, but the features of dependability and cheap operation remain the same. Two common types of HID lighting have been adapted for safe use in the garden and greenhouse, Metal Halide and High-Pressure Sodium.

Metal Halide light produces an intense light of a blue-white spectrum excellent for vegetative plant growth. Geraniums, marigolds, mums, zinnias, and violets all thrive under Metal Halide light, as do most vegetables. A plant grown under a halide light will often exhibit increased leaf growth, and strong stem and branch development. Roses grow hearty under metal halides, and seem to burst with buds before flowering time. A wonderful general purpose garden light.

High-Pressure Sodium Full Spectrum. (HPS) light puts off a complete full spectrum of light. These are the ideal light for all stages of growth. They have both blue and orange spectrums for vegetative and flowering growth. Due to these lamps having a full spectrum they are highly recommended. Perfect for any stage of growth, and excellent if you have plants at different life stages under one lamp. An example of a full spectrum bulb is the Sylvania Grolux.

High-Pressure Sodium. (HPS) light puts off an orange: shaded light which simulates the rich red hue of the autumn sun. Best as fruiting or flowering. lights, the HPS systems are often used In conjunction with metal halide for a complete balance of light spectrum in the garden. Flowers and vegetables finished off under HPS will show tighter, stouter blossoms with increased yields. HPS lights are commonly used in commercial greenhouses as starting lights and for supplemental light for off-season crops. Some types of plants respond particularly well to HPS lighting, such as the herbs dill and coriander.

Average Lumen Per Watt Output of Common Lamps

• 100 Watt Light Bulb - 17.5 Lumens per watt
• 400 Watt Fluorescent Tube - 22 lumens per watt
• 1000 Watt Metal Halide - 125 lumens per watt.
• 1000 Watt High Pressure Sodium - 140 lumens per watt

Controlling Pest & Disease

Since there is no soil in hydroponics, many, but not all plant diseases are eliminated. Well kept and clean growing environments are the best prevention when it comes to plant disease. Always remove dead or dying leaf matter and any unhealthy plants from your hydroponic garden.

If you are growing indoors, the chances of pest infestation are greatly reduced. In the event of pest problems, there are many biological controls available.

Water-Soluble Minerals (Nutrients in Solution)
(see Lesson 5 for more information)

As mentioned earlier, a hydroponic gardener uses minerals that are water soluble and ready to be taken up by the plant roots. Scientists and researchers have determined exactly what minerals a plant needs and in what quantities. A large number of hydroponic nutrient formulas have been developed and, although some have better results than others, there is no one perfect mixture. The success of each nutrient formula depends on the conditions it is used in and what plants are being grown.

Many hydroponic gardeners use a pre-mixed nutrient formula that they simply add water to. These formulas contain all the minerals and nutrients that a plant needs, in the correct proportions and are available in powder or liquid form.

The macro nutrients a plant needs include:

Nitrogen

Phosphorous

Calcium

Potassium

Sulfur

Magnesium

Iron

and the trace elements (used in minute quantities) a plant needs include:

Manganese

Boron

Zinc

Copper

House plants may be propagated asexually, in which all new plants will be identical, in most cases, to the parent plant, or sexually, where the new plants will not necessarily be identical to the parent plants. Plants are propagated sexually by seeds. Cuttings, air-layering, division and runners are asexual methods of propagation.

Seeds: Some plants like cactus and African violets can be raised in the home from seed. Plants grown from seeds take longer to reach maturity but are less costly than purchasing commercially available house plants. Variation among seedlings can make this method of propagation interesting.

There are many ways of germinating seed. Some are quite simple while others are complex. Basically, all are intended to provide seeds with the proper moisture and temperature conditions. Useful germinating media for seeds include sand, sphagnum moss, peat moss vermiculite, perlite, and a mixture of these media. Vermiculite and perlite, being sterile and relatively inexpensive, make excellent media for germinating seeds. Other germinating media should be pasteurized by placing them in a shallow pan in the kitchen oven. Heat the oven until the temperature of the media reaches 180°F. Maintain this media temperature for one-half hour and then remove from the oven.

For germinating seed, follow the following steps:

1. Place the pasteurized medium in a container which has a drainage hole in the bottom.
2. Moisten the medium by placing the container in a shallow pan of water. Remove when top of soil is moist.
3. Spread seeds in rows over surface of the medium.
4. Cover seeds according to directions on packet. Small seeds like African violets or begonia should not be covered.
5. Place container in polyethylene bag and seal the ends with tape or twist-ems.
6. Set container on a window sill in indirect sun. Temperature of 65 to 75°F.
7. No watering required until bag is removed.
8. Remove bag when first seedling leaves are present. Provide maximum amount of light required by seedlings.
9. Transplant, when first true leaves develop (usually the third leaf).

Cuttings: Cuttings are severed parent parts which produce roots and/or stems to form a new and independent plant. Stems, leaves, or roots may be used. Equipment needed for rooting cuttings include a container, rooting medium, a sharp knife, a plastic bag, a source of plant material and in some cases a rooting hormone. A rooting hormone is useful for encouraging rooting on difficult to root cuttings.

There are several methods of propagating plants by cuttings. All are intended to provide the cuttings with the proper moisture and temperature conditions just as with germinating seeds. Cuttings can be rooted in water, sand, perlite or vermiculite. Some plants are easy to root in water, but perlite or vermiculite generally give more satisfactory results.

Select cuttings from healthy plants. When taking cuttings, make all cuts clean and at an angle through the stem, making sure there is at least one node (joint) under the surface of the medium. Push the cuttings down in the medium about one inch. The medium should be moist but not soggy. Slip an airtight polyethylene bag over the cuttings and around the container. No further watering will be necessary. Place in a room at 60 to 70°F. Cuttings can be potted when they show an abundance of roots.

Types of Cuttings

Tip and Stem Cuttings: Tip cuttings (taken from the tip of plants) are used to propagate such common house plants as the velvet plant and jade plant. Tip cuttings are generally 3 to 5 inches long and are removed from the parent plant at a point just below a leaf (Figure 1).

Swedish ivy, pilea and fittonia can be propagated by stem cuttings (sections of stems with leaves attached). The cuttings should have three or four leaves for best rooting.

Cane Cuttings: Cane cuttings are used for propagating dumbcane, Chinese evergreen and similar plants which produce cane-like or leafless stems. The cane is cut up into small pieces 2 to 3 inches long. Place the cuttings on their sides slightly below the surface of the rooting medium. A bud will eventually sprout and form a new stem when the cutting is rooted (Figure 2).

Whole Leaf Cuttings: Whole leaf cuttings are prepared from leaves with or without their stalks (called petioles). Roots and leaves will eventually form at the base of the leaf (Figure 3). Peperomia and African violets are commonly started by whole leaf cuttings.

Leaf Section Cuttings: Leaf section cuttings can be used for propagating plants like the Rex begonia and snake plant. The leaves are cut into pieces, with the edge of the cuttings closest to the base of the parent plant inserted into the rooting medium (Figure 4).

Leaf Bud Cuttings: Leaf bud cuttings consist of a single leaf attached to a piece of 1 to 1 1/2 inch stem. The dormant bud, located where the leaf stalk joins the stem will give rise to a new shoot and branches (Figure 5). The cutting should be inserted in the rooting medium with the bud about 1/2 inch below the surface. English ivy is easily propagated by this method.

Cuttings from succulents or cactus should be allowed to dry for 1 to 7 days, depending upon species and size, before placing in a rooting medium. The drying period will cause the cut edges to callous. This will prevent the absorption of excessive amounts of moisture that could result in rotting.

Water pumps are designed to move water with no solids or particulates. Types of water that can be pumped include ground water, potable water, salt water and they can be used in light wastewater applications. Water pumps are widely used in water supply distribution applications, for irrigation, land / mine drainage, condensate transport, and for sump and bilge pumping.

Industrial water pumps are not so much a type of pump as they are a classification based on the media being transferred. Nearly every pump type that is defined by either a complementary application (fountain water pumps, submersible water pumps) or by motive type (such as centrifugal, cantilever, or hand water pumps) can be used in water service applications. The major influences over what type of pump to select are the specific application, the discharge flow and the discharge pressure required (high pressure water pumps are available), the size of the inlet and outlets to which the water pump will be connected, the temperature of the water that will be pumped (select a hot water pump specifically designed to transfer high temperature media), and whether or not the water must maintain some form of sterility.

One of the most important specifications to consider when selecting between the many available types of water pumps is the type of power source that will be required to run to pump. Electric water pumps are quite common. These include both AC and DC powered pumps (such as 12 volt water pumps). Gas powered water pumps and other fuel driven pumps (oil, gas, diesel, etc.) are both reliable, commonly available, and capable of generate high degrees of lift. Solar water pumps are also available. While solar powered water pumps are not generally able to provide the same motive forces as electric or gas driven water pumps, they are useful in small flow situations, especially in applications that require remote placement, or in places where regular supervision is not available.

pH

pH is the measurement of the hydrogen ion concentration in a particular medium such as water, soil, or nutrient solution. More simply, it refers to the acidity or alkalinity of that medium. PH is measured on a scale ranging from 0- 14, with 7 being neutral, above 7, alkaline and below 7, acidic.

The pH of a medium or nutrient solution is important to plant growth. Each plant has a preferred pH range. PH ranges beyond the preferred for a given plant may cause stunted growth or even death.

Very low pH (< 4.5) or high pH (> 9.0) can severely damage plant roots and have detrimental effects on plant growth.

As the pH level changes, it directly affects the availability of nutrients. The majority of nutrients are available to a plant at a pH range of 6.0 -7.5. Somewhere within that range is the ideal pH level for most plants. When pH levels are extremely high or extremely low, the nutrients become "locked" in solution and unavailable to the plant. At extremely low pH levels some micro-nutrients, such as manganese, may be released at toxic levels.

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