BASIC PRINCIPALS; Plant foliage requires light, oxygen and carbon dioxide. Plant root systems require water, nutrients and oxygen. When plants are grown normally water leeches nutrients from the soil and carries them to the roots. The water and nutrients are taken up by the roots to feed plant growth. Soil drainage then allows water to be replaced by air in the gaps between soil grains. This supplies the roots with oxygen.
In hydroponics the nutrients are dissolved in the water. Soil is replaced with a growing medium to supply the roots with water, nutrients and oxygen. Hydro juice (nutrient solution) can be drip fed to each plant, it can also be used to regularly flood the root chamber, then drain out. Both methods require a pump and timer to circulate the nutrients through the roots and are covered by these diagrams and notes. Roots can also be grown in the air by spraying roots with a fine mist of hydro juice, or grown in the hydro juice and the solution aerated under each root mass with an air pump. With both of the second two methods the plants must secured at the base of the stem or something.
The hydroponic system described does work and is suitable for any plant with stringy roots. I have not tried it with any bulb plants or plants such as orchids that require fungus or mold in the soil to grow. This method is similar to Nutrient Film Technique (NFT) the thin Rockwool slice acting as a capillary mat. This eliminates the need to have flat bottom the root chamber and to level the bottom of root chamber, making easier and cheaper to set up.
This method will get the most vigorous growth if each plant has it’s own continuos drip feed. The dripper is positioned drip on roots growing from the base of the seedling block, the roots will grow thick, hairy and compact under the dripper. 4L per hour dripper are used however their drip rate depends pressure, this is effected by height and size of the drip feed tank. The drip rate will slow as the tank empties.
Feeding can also be achieved with faster dripper at the top of each top end of each side of the root chamber. The plants grown like this had a large root mass, the roots of three plant taking up about a third of the root chamber. With the timer I had could only flood the root chamber every 4 hours, the growth rate was similar to the last. The growth rate will improve by flooding every hour or even less. After the root chamber is flooded it should drain to a trickle in a few minutes.
STARTING PLANTS; Soak seeds in damp paper or cotton wool, cover seed with damp paper or cloth, drian off excess water and don’t allow to dry out. When the seed root is 2 – 5mm. long place the seed root first in the small hole with tweezers (fig.3). Make sure the root is protected by the open jaws of the tweezers and that the seed or root isn’t squashed. Then place seedling block hole up on a plate and wet Rockwool until it won’t take any more water. Keep the plate on an angle for drainage, but the seedling blocks shouldn’t dry out too much and seedling should come up in a few days. Seedlings can stay on the plate until roots grow from the bottom or sides of the seedling block (fig.4).When this happens seedling are ready to transplanted on to the Rockwool mat in the root chamber. (Before the seedling blocks go into the root chamber the rookwool is soaked in water 24 hours then with hydro juice at half strength.) Roots will grow from seedling block, through and along the under side of the Rockwool mats. Place three to eight plants per side, evenly spaced along the slot, and it will soon grow into mass of green. When the system is operational and plants are growing, the inside of the root chamber should have a rich earthy smell. Three or four plants if your growing them big (outdoors ), eight if your growing fast and flowering early ( under lights ).
When the roots grow from the bottem or sides of the Rockwool block it’s ready to transplant into the grow tube. Once the roots have grown into the mat tou can hit them with full stength hydro juice. Light proof plastic should be used to cover the top of the root chamber white side up, this is to stop green slime growing on the rockwool. This can only be done when the plant is tall enough, take care not strain or damage the plant.
Many seeds require special conditions to germinate. For example, most garden vegetables and herb seeds need to remain damp or wet for some time.
Seeds can be germinated in a hydroponic grower, and often they germinate even better than in soil.
Most seeds are placed below the surface of the media. A suggested placement is from ½ to 1 inch below the surface. This keeps the seed very moist and will give it some feel for when the light is and where the dark is. The root of the plant will grow down towards the dark and the water, and the plant stem and leaves will go towards the light.
Many seed packets include instructions for soil and mention how deep to bury the seeds. They can be planted at the same depth in hydroponics.
Some seeds, like beans and corn, will germinate in just a few days. Some others, such as tomato, bell pepper and herbs may take as long as two weeks until they appear. Growers with seeds should be watered each day although no plants are showing. If you do not see any sign of life after two weeks, it is best to replant the grower.
Occasionally the grower root area will be so cold or so dry, the seeds will not germinate.
To germinate very small seeds like many herbs, a special form of germination may be required. One way is to start the seeds between two pieces of paper or a towel soaked with water. The towel is kept moist each day.
Germinating some types of seeds is more complicated than just soaking in water. Some seeds need to be damaged in some way to germinate, and others are specialized to respond to periods of temperature or light. If there something you would like to grow, it might help to learn what the seed requirements are to germinate.
Other Methods of Reproducing
Some plants can reproduce from cuttings. This means cutting a small part of the growing tip of a plant, pulling off the bottom leaves and sticking the cut end into the growing media. Some of the plants that can be reproduced from cuttings are basils and many of the herbs.
Garlic reproduces from individual garlic cloves. Some of the garlic in the grocery store is treated and will not sprout. An organic garlic is more likely to sprout.
Potatoes are grown from a planted potato. The potato can be cut into pieces or planted whole.
ROOT CHAMBER; The Root Chamber is made from 90mm. PVC storm water pipe. This type is used for all new building constructions so off cut are about. A selection of 90mm. PVC storm water pipe and 90mm. fittings are available at large hardware stores. Fittings include right angles, tee junctions, end caps and others. These can be used to make the root camber suit any room. The root camber show in Diagrams (fig.5,6,7) is made with two lengths about 1 miter for the sides, 2 lengths about of 600mm. for the ends and 4 right angles for the corners. PVC pipe glue is used to make all joins water tight. A slot is cut in the top of each side providing access to change growing medium and remove root mass. Holes instead of a slot may be used for each plant but another way of access must be used. A drain hole or holes are drilled in the bottom of one end of the root chamber and a flood hole is drilled in the top of the other end. The root chamber is mounted on an angle with drain end below then the flood end. This is to ensure that the roots don’t get water logged. Too much of an angle will cause the Rockwell and roots to dry out at the high end.
FLOOD AND DRAIN.
A flood and drain system requires a timer, a pump and a drain tank to catch the hydro juice. Hose is run from the bottom of the drain tank to the pump inlet. Hose is run from pump outlet to the hole in the top of the flood (high) end of the root chamber. The pump inlet is below the bottom the drain tank. As the drain tank is filling hydro juice flows through to the pump inlet through the pump and up the flood hose till level with the hydro juice in the tank. This is to prime the pump as the pump can’t suck air, it can only push out what flows in the inlet. The timer runs the pump for 1 minute and the hydro juice fills about half the root chamber. If chamber over flows increase size of drain holes. If a hose is used at the drain end, it must not cause hydro juice to stand at the drain end. A recycling type bin is ideal for the drain tank (see end of Drip Feed section to attach hose to drain tank). Putting the pump on the floor and the drain tank on bricks should raise it enough prime the pump.
EBB AND FLOW (FLOOD AND DRAIN)
The Ebb and Flow system works by temporarily flooding the grow tray with nutrient solution and then draining the solution back into the reservoir. This action is normally done with a submerged pump that is connected to a timer. When the timer turns the pump on nutrient solution is pumped into the grow tray. When the timer shuts the pump off the nutrient solution flows back into the reservoir. The Timer is set to come on several times a day, depending on the size and type of plants, temperature and humidity and the type of growing medium used. The Ebb and Flow is a versatile system that can be used with a variety of growing mediums. The entire grow tray can be filled with Grow Rocks, gravel or granular Rockwool. Many people like to use individual pots filled with growing medium, this makes it easier to move plants around or even move them in or out of the system. The main disadvantage of this type of system is that with some types of growing medium (Gravel, Growrocks, Perlite), there is a vulnerability to power outages as well as pump and timer failures. The roots can dry out quickly when the watering cycles are interrupted. This problem can be relieved somewhat by using growing media that retains more water (Rockwool, Vermiculite, coconut fiber or a good soiless mix like Pro-mix or Faffard’s).
Drip Feed System.
This feed system has a dripper for each plant. Dripping the hydro juice directly on the top of the root mass should stop the plant from sending out long roots in search of food. Resulting in more growth on top or so the theory goes. The drip system uses a drip feed tank about one meter above the drippers and reticulation system.
Reticulation is via 13mm. poly tube to just above the root chamber. A hole is punched in the 13mm. tube. A 4mm. adapter is screwed into the hole. Then 4mm. poly tube is attached to the 4mm. adapter. A dripper is attached to the other end of the 4mm. tube. The 4mm poly tube should be kept as short as possible so there is enough pressure to start the drippers. Barbed right angles and tee’s are used to route the 13mm. poly tube close to each plant. The top of the 13 mm. poly tube is about 50mm. below the bottom of the drip feed tank. A 13mm. to snap-on adapter is fitted to the top of the 13mm. poly tube. If the 13 mm. poly tube is positioned at right angles to the slot and the 4mm. adapter, 4 mm. poly tube and the dripper positioned over the slot. Any leakage at the joins in the poly tube will drip into the slot preventing loss of hydro juice.
A 42 liter plastic garbage bin and lid is used for the drip feed tank. Snap-on fittings and 13mm. garden hose connect the bottom of the drip feed tank to the to 13mm. poly tube. They also connect the pump outlet hose to the top of the drip feed tank. A Stop Snap-on is used where the garden hose connects to the Snap-on adapter on the 13mm. poly tube. This prevents the hydro juice flowing from when the Snap-on is removed from the 13mm. poly tube. To convert from flood and drain to drip feed. Move the pump outlet hose from the flood inlet on top of the root chamber, to the top of the drip feed tank.
Snap-on universal sprinkler adapter are used to connect hoses to the side of the drip feed tank . These are a Snap-on to 13mm. thread adapter. There is also a 20mm. thread that screws onto a 13mm. thread. A hole no larger than the 13mm. thread is drilled in the side of the tank. The 13mm. thread is pushed through the hole from the outside of the tank. Now the 20mm. thread is screwed on to the 13mm. thread inside the tank creating a water tight seal. Make sure the hole is away from obstructions inside the tank that would prevent the 20mm. thread from attaching to the 13mm. thread. This method is used for all tanks and also for the pump outlet hose connection to the top of the flood end of the root chamber.
Drip systems are probably the most widely used type of hydroponic system in the world. Operation is simple, a timer controls a submersed pump. The timer turns the pump on and nutrient solution is dripped onto the base of each plant by a small drip line. In a Recovery Drip System the excess nutrient solution that runs off is collected back in the reservoir for re-use. The Non-Recovery System does not collect the run off.
A recovery system uses nutrient solution a bit more efficiently, as excess solution is reused, this also allows for the use of a more inexpensive timer because a recovery system doesn’t require precise control of the watering cycles. The non-recovery system needs to have a more precise timer so that watering cycles can be adjusted to insure that the plants get enough nutrient solution and the runoff is kept to a minimum.
The non-recovery system requires less maintenance due to the fact that the excess nutrient solution isn’t recycled back into the reservoir, so the nutrient strength and pH of the reservoir will not vary. This means that you can fill the reservoir with pH adjusted nutrient solution and then forget it until you need to mix more. A recovery system can have large shifts in the pH and nutrient strength levels that require periodic checking and adjusting.
12 Plant Patio Table Garden System.
Drill the 12 holes for the bottles and two in the center for the overflow pipe. Make sure you drill between the braces under the table.
The 1/2 inch PVC pipe is hidden under the table where it isn’t seen from the top.
Hydroponic gardening can be VERY complicated, with computers and sensors controlling everything from watering cycles to nutrient strength and the amount of light that the plants receive.
On the other hand, hydroponics can also be incredibly simple, a hand watered bucket of sand with a single plant is also a method of hydroponic gardening. Most hobby oriented hydroponics systems are somewhere between the two extremes mentioned above.
The “average” home hydroponic system usually consists of a few basic parts: a growing tray, a reservoir, a simple timer controlled submersible pump to water the plants and an air pump and air stone to oxygenate the nutrient solution. Of course, light (either natural or artificial) is also required.
Hydroponic gardening can be VERY complicated, with computers and sensors controlling everything from watering cycles to nutrient strength and the amount of light that the plants receive.
On the other hand, hydroponics can also be incredibly simple, a hand watered bucket of sand with a single plant is also a method of hydroponic gardening. Most hobby oriented hydroponics systems are somewhere between the two extremes mentioned above.
The “average” home hydroponic system usually consists of a few basic parts: a growing tray, a reservoir, a simple timer controlled submersible pump to water the plants and an air pump and air stone to oxygenate the nutrient solution. Of course, light (either natural or artificial) is also required.
History of Hydroponics.
Hydroponics basically means working water (“hydro” means “water” and “ponos” means “labor”). Many different civilizations have utilized hydroponic growing techniques throughout history. As noted in Hydroponic Food Production (Fifth Edition, Woodbridge Press, 1997, page 23) by Howard M. Resh: “The hanging gardens of Babylon, the floating gardens of the Aztecs of Mexico and those of the Chinese are examples of ‘Hydroponic’ culture. Egyptian hieroglyphic records dating back several hundred years B.C. describe the growing of plants in water.” Hydroponics is hardly a new method of growing plants. However, giant strides have been made over the years in this innovative area of agriculture.
Throughout the last century, scientists and horticulturists experimented with different methods of hydroponics. One of the potential applications of hydroponics that drove research was for growing fresh produce in nonarable areas of the world. It is a simple fact that some people cannot grow in the soil in their area (if there is even any soil at all). This application of hydroponics was tested during World War II. Troops stationed on nonarable islands in the Pacific were supplied with fresh produce grown in locally established hydroponic systems. Later in the century, hydroponics was integrated into the space program. As NASA considered the practicalities of locating a society on another plant or the Earth’s moon, hydroponics easily fit into their sustainability plans. This research is ongoing.
But by the 1970s, it wasn’t just scientists and analysts who were involved in hydroponics. Traditional farmers and eager hobbyists began to be attracted to the virtues of hydroponic growing. A few of the positive aspects of hydroponics include:.
● The ability to produce higher yields than traditional, soil-based agriculture
● Allowing food to be grown and consumed in areas of the world that cannot support crops in the soil
● Eliminating the need for massive pesticide use (considering most pests live in the soil), effectively making our air, water, soil, and food cleaner
Commercial growers are flocking to hydroponics like never before. The ideals surrounding these growing techniques touch on subjects that most people care about, such as helping end world hunger and making the world cleaner. In addition to the extensive research that is going on, everyday people from all over the world have been building (or purchasing) their own systems to grow great-tasting, fresh food for their family and friends. Educators are realizing the amazing applications that hydroponics can have in the classroom. And ambitious individuals are striving to make their dreams come true by making their living in their backyard greenhouse, selling their produce to local markets and restaurants.
Crops produced in today’s modern greenhouse ranges are many and varied. They can be loosely categorized as follows:
● vegetables including tomatoes, cucumbers, fancy lettuces, bell peppers, cherry tomatoes and a host of minor ones such as radish, melon and strawberry
● cut flowers e.g. roses, mums, carnations
● potted flowers e.g. geraniums, azalea, poinsettia, tulip
● numerous bedding plants
Porous, well aerated substrate are used as anchorage for the plants root system and feeding area. Rockwool and Heydite are the most popular as they are most readily available, and easiest to use and transport. There are various other mediums which are not as widely used.
There are different ways to bring water to the plants.
● Nutrient Film Technique,
● Drip-Irrigation or Micro-Irrigation,
● Aeroponics / Deep Water Culture,
● Flood & Drain,
● Home Hobbyist Systems,
● Passive Planters / Hydroculture.
Carbon Dioxide Enrichment
In an outdoor garden the CO2 level in the air is about 300 parts per million (ppm). Plants thrive when they are able to take in a higher level of CO2. Growers today monitor their greenhouse CO2 levels with special purpose control monitors which in turn operate CO2 burners or generators to replenish CO2 consumed by the plants.
HAF (Horizontal Air Flow)
Working with CO2 enrichment and indeed an important part of the greenhouse environment is horizontal air flow. Conceived in the late seventies following research involving finer aspects of greenhouse air circulation, horizontal air flow, or HAF as it is now referred to, is widely used.
Commercial growers end up with very sizeable portions of their yearly turnover as work-in-process. The closer the crop gets to harvest, the higher the risk of catastrophic loss, should a key part of the greenhouse’s climate control system fail. Accordingly, growers go to great lengths to protect themselves. Early warning is a vital part of their security. Most now employ automatic phone dialers with electronic voice simulation to alert them of impending problems long before serious crop damage can occur.
Environmental concerns are uppermost in the minds of today’s consuming public. The horticultural industry has been working for many years to reduce its dependence on chemical pesticides, many of which have been linked to cancers. Numbers of key pesticides have been deregistered for particular crops, others have been removed from the market altogether. Promising advances have been made in the use of predator insects in greenhouse ranges as natural biological control against pest insects. While much work remains to be done to educate the grower in their use, progressive members of the industry are now well on their way to 100% biological insect control.
Until recently, pollination of greenhouse tomato crops was accomplished with a labourious method of fruit truss vibration utilizing battery operated hand-held vibrators (“electric bees”) manually touched against mature flower sets. It was a strictly artificial way of simulating natural pollination in the absence of a natural outdoor environment where wind and insects are the vectors. In today’s modern tomato ranges, hives of bumble bees are placed strategically amongst the crop and left to accomplish naturally what has been, until now a monotonous and tedious task for greenhouse staff.
In order to get the best possible results from a Controlled Environment Agriculture System, we will need to bring the spectrum and intensity of sunlight indoors. This is accomplished using High Intensity Discharge lamps. These lamps, in conjunction with specially designed luminaries, will reflect light downwards to plants, where it may be utilized to the maximum.
Modern greenhouses employ advanced environment control aids such as relays, humidistats, thermostats, CO2 injection systems and fans which are often controlled by a central computer. Smaller systems employ various individual control units.
The organic hydroponic display or Bioponics, we believe, is of significant interest to both commercial and hobby growers. This method employs an organic tea based nutrient solution with added microbial agents to facilitate their breakdown into mineral elements which plants are able to take in.
Controlled Environment Agriculture Systems
Today’s commercial greenhouses are constructed of galvanized steel, extruded aluminum, fibreglass, polycarbonate, acrylic, polyethylene and glass. The percentage of each, comprising a typical structure, varies by type of design.
Loosely categorized, the following basic shapes and styles are prevalent:
● freestanding grade to grade hoop houses (quonset) clad in polyethylene, double polyethylene, corrugated fibreglass sheet, or plastic composite structured panels
● linked or gutter-connected straight-wall hoop houses clad in polyethylene, double polyethylene and so on as above
● linked or gutter-connected straight-wall hoop houses clad in curved automotive glass
● linked or gutter-connected straight-wall peaked houses clad in flat tempered glass. This style of range breaks down into three further subcategories:
– single peak gutter-to-gutter
– double peak with floating gutter
– triple peak with two floating gutters
All of the above styles or designs of greenhouses are popular, the grower selecting which he will build based on crop to be grown, usage pattern, seasonal pattern, as well as economic considerations.
● Nutrient control insures that the plants get the minerals they need at the right pH and temperature.
● Faster growth then soil grown plants.
● No weeds. The medium is mostly inert and unless it is out doors, there is no way for weed seeds to get into the growing medium.
● No guess work about what nutrients are going to the plant.
● Easy to correct for plant deficiencies.
● No backbreaking soil conditioning.
● The water has all the nutrients that is required by the plants. The roots don’t have to grow bigger looking for food. The growth of the plant goes mostly to the upper plant.
● Plants can be spaced closer together then in soil. Spacing is dependent only on the space needed to supply adequate light to the plant.
● Garden can be at a good working height.
● Up to twenty times the amount of plants can be grown in the same space in hydroponics then in soil.
● No soil to harbor bugs.
● Healthy plants have better taste.
● Healthy plants resist insect infestations. Less insecticide is needed.
● Educational for children of all ages learning about plant growth.
● Faster growth so that more then one crop can be raised in a season.
● Can be made portable so that you can move it from classroom to classroom or take it with you when you move.
● Ground is left undisturbed on rented property.
● Condensed growing methods make better use of greenhouse space.
● Consumes 1/10 the water that field crops do.
● Conversation piece.
● Good past time for those that likes to tinker.
● It’s something the Jones’ don’t have. 🙂
Some disadvantages to growing plants in hydroponics are;
● Higher cost to get started then soil culture.
● System failure could result in a lost crop if not caught right away. Some systems can go days before damage occurs.
All the plants needs are supplied by water. The roots are placed in an inert growing medium. Water, enriched with all the nutrients the plants need, is supplied to the roots by several different methods.
1. Aeroponics; the roots are sprayed with the nutrient solution. This method ensures that the roots get plenty of oxygen to the root system. It has not been proven that this method helps to make plants grow any faster then in other methods. It has some inherent problems such as nozzles getting plugged up. One of the more expensive methods of hydroponics.
2. Ebb and flow; also called flood and drain. Periodically floods the medium. As the water drains out new air comes in. Not as hard to maintain as an aeroponics system. Roots can plug up waterways however.
3. NFT; the Nutrient Film Technique is one of the methods most often used by commercial growers. Plant roots are contained in a channel through which a thin “film” of nutrient solution passes. The nutrient solution is aerated and recycled with the addition of makeup water.
4. Run to waste; in this method the nutrient is fed to the plants at near the same rate as the plants use the water. In all the other methods, the nutrient solution returns to a tank to be recycled. This system is the cheapest to get started, however, it requires a lot of monitoring to insure the plants are getting enough nutrient but at the same time not getting too much nutrient. Plants will only take up the nutrients it needs. On sunny days they take up mostly water and leave the nutrients behind to build up. The built up salts must be purged from the system one or two times a week. This system wastes the most nutrients.
Plants most generally have to be stared in a small amount of medium before they can be placed in the growing area. Seeds are started with no nutrients in the water. Seeds have their own food and don’t require any additional nutrients until the first set of leaves appear. Nutrient is added at half strength to encourage root development until it’s transplanted. Then full strength nutrients are used for the rest of the plants growth. There are two kinds of formulas for plants. One promotes the vegetative growth and the other promotes Fruiting. A system that has both types of plants will have to have one or the other formulas depending on which crop is more important. There are two methods of growing systems, horizontal and vertical. The following are systems:
● Bag culture; used commercially in run to waste systems. The hobbyiest can also use this inexpensive method in a recirculating system. Bags are filled with a lightweight medium and nutrient is fed to each bag by inexpensive spaghetti tubes. Has the advantage of being able to space the plants as they mature.
● Tomatoes in bag culture.
● Gutter/NFT; A lot of hobbyiests have tried just about everything with this type system.
1. Manufactured channels; Square corners help to prevent damming.
2. Rain gutter; Metal gutter can oxidize and add undesirable materials to the nutrient
solution. Line with plastic sheet. Plastic gutters require total support to keep it strait.
3. PVC pipe; most hobbyiests use PVC pipes with holes drilled for plants. This system is usually more expensive then bag culture. Too often the roots clog up the waterways and dam the water causing root rot. Aeration in the root zone may become a problem.
● Beds; are extra wide channels. Beds can be filled with a growing medium or pots can be placed in the bed so that they will pick up the water from the bed through a wicking action. Pots are the most versatile. Plants can be spaced to meet the plants needs. I use this method for houseplants and for starting seeds. A 1/4 inch of water can be maintained in beds with pots. Water must be drained well in filled beds. Beds can be made from any material that will hold the weight of the plants and the medium. A plastic film can be used to line construction. Nutrient solution is usually aerated and returned to the bed.
Although there is no soil in a hydroponic garden, the plants must still be anchored. There is a wide range of inert materials which can be used to support plant roots and we call them “growing mediums”. Heydite, clay pellets, Perlite, vermiculite, and Rockwool are the most popular media. The hydroponic media that work best are pH neutral, provide ample support for plants, retain moisture, and allow space for good air exchange. The type of media you choose will depend on the size and type of plants you wish to grow, and the type of hydroponic system being used. For continuous drip systems, course media such as Heydite (a porous shale) or Hydrocorn (clay pellets) are best. The 1/4 ” to3/4 ” pebbles provide enough free drainage and air space to take advantage of continuous feeding. These media also provide good anchorage for larger plants, and are easy to clean and re-use indefinitely.
Rockwool is also another popular medium. Made from rock which has been melted and spun into fibrous cubes and growing slabs with the texture of insulation, Rockwool provides roots with a good balance of water/oxygen. Small cubes are used for starting seeds and cuttings, 3″ or 4″ cubes for small plants or intermediate growth, and slabs for larger plants. Rockwool can be used with continuous drip or flood and drain systems. Although it is possible to sterilize and re-use Rockwool, most often it is used only once.
Perlite, made from volcanic rock, is a white, light weight material often used as a soil additive. The 1/8″ to 1/4″ pellets can be used alone as growing medium, but don’t provide enough anchorage for large plants. Perlite is often used to start seed and cuttings, which can easily transplanted after rooting. Vermiculite is use the same way as Perlite, and the two are sometimes mixed together. It is made from heat expanded mica and has a flaky, shiny appearance. Soilless mix such as Pro-mix BX, and Pro-mix lite has the appearance and texture of light soil. Mainly peatmoss, mixed with Perlite, it contains very little nutrient, and is used a a soil additive, or alone as a hydroponic medium.
Some hydroponic systems do not require any growing medium at all. Various methods are used to support the plants while the roots are directly fed nutrient solution. Some examples of these are, aeroponic, N.F.T., or “Nutrient Film Technique” and deep water culture.
Nutrient Film Technique.
The purist form of today’s highly developed hydroponic growing systems is Nutrient Film Technique (N.F.T.). It is also the form of hydroponics most intriguing to the public because of its futuristic nature and appearance.
The nutrient is fed into growtubes where the roots draw it up. The excess drains by gravity back to the reservoir. A thin film of nutrient allows the roots to have constant contact with the nutrient and the air layer above at the same time.
Drip-Irrigation or Micro-Irrigation
Today’s greenhouse irrigation systems employ, to an ever-increasing extent, the concept of drip or microirrigation. It entails a principle of minimized water consumption with maximized plant benefit. There are literally hundreds of emitting/dripping/trickling/micro-spraying/etc. devices on the market today for the commercial/hobbyist grower to choose from.
A submersed pump feeds nutrients solution through header tubes to secondary feed lines connected to drip emitters.
A controlled amount of solution is continuously drip-fed over the medium and root system. Another tube is connected to the lower part of the garden system to recover the solution.
Aeroponics / Deep Water Culture
Plant roots are suspended in highly oxygenated nutrient solution allowing easy inspection and pruning of roots. Air pumps, compressors or Oz injectors provide oxygen which is crucial to healthy plant growth. The simplicity and affordability of these very active systems make them popular with home hobbyists and commercial growers alike.
In an Aeroponic system the roots are misted within a chamber. A pump pushes the water with nutrient solution through sprayers, keeping the roots wet while providing a maximum amount of oxygen.
This technique is an excellent way to propagate cuttings.
Deep Water Culture is another form of aeroponics. The root system of a plant grown in Deep Water
Culture is immersed in water with a bubbling aerator keeping the roots oxygenated.
This technique is very good to use with plants that are heavy feeders.
Flood & Drain
Flood & Drain systems are similar to N.F.T. systems. They are ideal for multiple plant per square foot growing where individual plant inspection is difficult. They are also very popular as propagation tables.
A plastic growing tray is flooded periodically by a submersed pump connected to a digital timer (or the ControlFreak!). Medium and root system are soaked, then drained (via gravity back through the pump) at specific intervals.
Various mediums can be used, Rockwool is the most popular with Flood & Drain systems.
The Ebb & Flow trays are examples of the Flood & Drain system.
Home Hobbyist Systems
There are a number of compact hydroponic systems and kits most popular with home hobbyists, researchers and teachers. These are made to be especially attractive to children in order to get their attention and interest. Hobby systems include deep water and aeroponic systems which are scaled down versions of commercial systems.
Passive Planters / Hydroculture
This is probably the most commonly know form of hydroponics. These systems do not require a water or air pump and are therefore called passive systems. Passive Planters have been used in office buildings and restaurants for many years.
Hydroculture planters utilize a clean, porous growing medium to support plant roots. A nutrient reservoir in the base of the growing container allows the plants to take as much or as little water as they require. Water level indicators show exactly when and how much to water. Clean, odourless and non-allergenic, hydroculture or passive planters are ideal for every environment.
Beginner’s Growing Tips.
This page has been designed to help answer the important questions beginning growers might have when just getting started in hydroponics. A lot of these concepts are connected to each other. Follow the links and put the pieces of this growing puzzle together.
The more you know, the easier it is to grow!
During photosynthesis, plants use carbon dioxide (CO2), light, and hydrogen (usually water) to produce carbohydrates, which is a source of food. Oxygen is given off in this process as a by-product. Light is a key variable in photosynthesis.
Measuring nutrient solution strength is a relatively simple process. However, the electronic devices manufactured to achieve this task are quite sophisticated and use the latest microprocessor technology. To understand how these devices work, you have to know that pure water doesn’t conduct electricity. But as salts are dissolved into the pure water, electricity begins to be conducted. An electrical current will begin to flow when live electrodes are placed into the solution. The more salts that are dissolved, the stronger the salt solution and, correspondingly, the more electrical current that will flow. This current flow is connected to special electronic circuitry that allows the grower to determine the resultant strength of the nutrient solution.
The scale used to measure nutrient strength is electrical conductivity (EC) or conductivity factor (CF). The CF scale is most commonly used in hydroponics. It spans from 0 to more than 100 CF units. The part of the scale generally used by home hydroponic gardeners spans 0-100 CF units. The part of the scale generally used by commercial or large-scale hydroponic growers is from 2 to 4 CF. (strength for growing watercress and some fancy lettuce) to as high as approximately 35 CF for fruits, berries, and ornamental trees. Higher CF values are used by experienced commercial growers to obtain special plant responses and for many of the modern hybrid crops, such as tomatoes and some peppers. Most other plant types fall between these two figures and the majority is grown at 13-25 CF. –Rob Smith
When a seed first begins to grow, it is germinating. Seeds are germinated in a growing medium, such as perlite. Several factors are involved in this process. First, the seed must be active–and alive–and not in dormancy. Most seeds have a specific temperature range that must be achieved. Moisture and oxygen must be present. And, for some seeds, specified levels of light or darkness must be met. Check the specifications of seeds to see their germination requirements.
The first two leaves that sprout from a seed are called the seed leaves, or cotyledons. These are not the true leaves of a plant. The seed develops these first leaves to serve as a starting food source for the young, developing plant.
Soil is never used in hydroponic growing. Some systems have the ability to support the growing plants, allowing the bare roots to have maximum exposure to the nutrient solution. In other systems, the roots are supported by a growing medium. Some types of media also aid in moisture and nutrient retention. Different media are better suited to specific plants and systems. It is best to research all of your options and to get some recommendations for systems and media before making investing in or building an operation. Popular growing media include:
● Composted bark. It is usually organic and can be used for seed germination.
● Expanded clay. Pellets are baked in a very hot oven, which causes them to expand, creating a porous end product.
● Gravel. Any type can be used. However, gravel can add minerals to nutrient. Always make sure it is clean.
● Oasis. This artificial, foam-based material is commonly known from its use as an arrangement base in the floral industry.
● Peat moss. This medium is carbonized and compressed vegetable matter that has been partially decomposed.
● Perlite. Volcanic glass is mined from lava flows and heated in furnaces to a high temperature, causing the small amount of moisture inside to expand. This converts the hard glass into small, sponge-like kernels.
● Pumice. This is a glassy material that is formed by volcanic activity. Pumice is lightweight due to its large number of cavities produced by the expulsion of water vapor at a high temperature as lava surfaces.
● Rockwool. This is created by melting rock at a high temperature and then spinning it into fibers.
● Sand. This medium varies in composition and is usually used in conjunction with another medium.
● Vermiculite. Similar to perlite except that it has a relatively high cation exchange capacity-meaning it can hold nutrients for later use.
There are a number of other materials that can (and are) used as growing media. Hydroponic gardeners tend to be an innovative and experimental group.
The apparatuses used in hydroponic growing are many and varied. There are two basic divisions between systems: media-based and water culture. Also, systems can be either active or passive. Active systems use pumps and usually timers and other electronic gadgets to run and monitor the operation. Passive systems may also incorporate any number of gadgets. However, they to not use pumps and may rely on the use of a wicking agent to draw nutrient to the roots.
Media-based systems–as their name implies–use some form of growing medium. Some popular mediabased systems include ebb-and-flow (also called flood-and-drain), run-to-waste, drip-feed (or top-feed), and bottom-feed.
Water culture systems do not use media. Some popular water culture systems are raft (also called floating and raceway), nutrient film technique (NFT), and aeroponics.
Think of a plant as a well-run factory that takes delivery of raw materials and manufactures the most wondrous products. Just as a factory requires a reliable energy source to turn the wheels of its machinery, plants need an energy source in order to grow.
Usually, natural sunlight is used for this important job. However, during the shorter and darker days of winter, many growers use artificial lights to increase the intensity of light (for photosynthesis) or to expand the daylight length. While the sun radiates the full spectrum (wavelength or color of light) suitable for plant life, different types of artificial lighting are selected for specific plant varieties and optimum plant growth characteristics. Different groups of plants respond in physically different ways to various wavelengths of radiation. Light plays an extremely important role in the production of plant material. The lack of light is the main inhibiting factor in plant growth. If you reduce the light by 10 percent, you also reduce crop performance by 10 percent.
Light transmission should be your major consideration when purchasing a growing structure for a protected crop. Glass is still the preferred material for covering greenhouses because, unlike plastic films and sheeting, its light transmission ability is indefinitely maintained.
No gardener can achieve good results without adequate light. If you intend to grow indoors, avail yourself of some of the reading material that has been published on this subject. If you are having trouble growing good plants, then light is the first factor to question. –Rob Smith
A large part of the success in growing hydroponically is planning where to place the plants. Grow plants that have similar growing requirements in the same system. Placing your system 1-2 feet away from a sunny window will give the best results for most herbs and vegetables. Even your regular house lights help the plants to grow. Make sure that all of the lights are out in your growing area during the night. Plants need to rest a minimum of 4 hours every night. If your plants start to get leggy (too tall and not very full), move the system to a spot that has more sun. Once you find a good growing area, stick to it. Plants get used to their home location. It may take some time to get used to a new place. –Charles E. Musgrove
Plants need around 16 mineral nutrients for optimal growth. However, not all these nutrients are equally important for the plant. Three major minerals–nitrogen (N), phosphorus (P), and potassium (K)–are used by plants in large amounts. These three minerals are usually displayed as hyphenated numbers, like “15-30-15,” on commercial fertilizers. These numbers correspond to the relative percentage by weight of each of the major nutrients–known as macronutrients–N, P, and K. Macronutrients are present in large concentrations in plants. All nutrients combine in numerous ways to help produce healthy plants. Usually, sulfur (S), calcium (Ca), and magnesium (Mg) are also considered macronutrients.
These nutrients play many different roles in plants. Here are some of their dominant functions:
● Nitrogen (N)–promotes development of new leaves
● Phosphorus (P)–aids in root growth and blooming
● Potassium (K)–important for disease resistance and aids growth in extreme temperatures
● Sulfur (S)–contributes to healthy, dark green color in leaves
● Calcium (Ca)–promotes new root and shoot growth
● Magnesium (Mg)–chlorophyll, the pigment that gives plants their green color and absorbs sunlight to make food, contains a Mg ion –Jessica Hankinson
Boron (B), copper (Cu), cobalt (Co), iron (Fe) manganese (Mn), molybdenum (Mo), and zinc (Zn) are only present in minute quantities in plants and are known as micronutrients. Plants can usually acquire adequate amounts of these elements from the soil, so most commercial fertilizers don’t contain all of the micronutrients. Hydroponic growers, however, don’t have any soil to provide nutrients for their plants. Therefore, nutrient solution that is marketed for hydroponic gardening
contain all the micronutrients. –Jessica Hankinson
In hydroponics, nutrient solution–sometimes just referred to as “nutrient”–is used to feed plants instead of plain water. This is due to the fact that the plants aren’t grown in soil. Traditionally, plants acquire most of their nutrition from the soil. When growing hydroponically, you need to add all of the nutrients a plant needs to water. Distilled water works best for making nutrient. Hydroponic supply stores have a variety of nutrient mixes for specific crops and growth cycles. Always store solutions out of direct sunlight to prevent any algae growth. See also conductivity, macronutrients, and micronutrients.
Disposal Unlike regular water, you need to be careful where you dispose of nutrient. Even organic nutrients and fertilizers can cause serious imbalances in aquatic ecosystems. If you do not live near a stream, river, lake or other water source, it is fine to use old nutrient on outdoor plants and lawn. Another possibility is to use it on houseplants. However, if you live within 1,000 feet of a viable water source, do not use your spent nutrient in the ground.
The ends of a plant’s roots aren’t open-ended like a drinking straw and they definitely doesn’t suck up a drink of water or nutrients. Science is still seeking a complete understanding of osmosis, so to attempt a full and satisfactory description of all that’s involved in this process would be impossible. However, we can understand the basic osmotic principle as it relates to plants.
First, consider a piece of ordinary blotting paper, such as the commonly used filter for home coffee machines. The paper might appear to be solid. However, if you apply water to one side of it, you’ll soon see signs of the water appearing on the opposite side. The walls of a feeding root act in much the same way. If you pour water onto the top of the filter paper, gravity allows the water to eventually drip through to the bottom side. Add the process of osmosis and water that’s applied to the bottom side drips through to the top.
With plants, this action allows water and nutrients to pass through the root walls from the top, sides, and bottom. Osmosis is the natural energy force that moves elemental ions through what appears to be solid material. A simplistic explanation for how osmosis works, although not 100 percent accurate, is that the stronger ion attracts the weaker through a semipermeable material. So, the elements within the cells that make up plant roots attract water and nutrients through the root walls when these compounds are stronger than the water and nutrients applied to the outside of the roots.
It then follows that if you apply a strong nutrient to the plant roots–one that’s stronger than the
compounds inside of the root–that the reverse action is likely to occur! This process is called reverse osmosis. Many gardeners have at some time committed the sin of killing their plants by applying too strong a fertilizer to their plants, which causes reverse osmosis. Instead of feeding the plant, they have actually been dragging the life force out of it.
Understanding how osmosis works, the successful grower can wisely use this knowledge to promote maximum uptake of nutrients into the plants without causing plant stress–or worse, plant death–from over fertilizing. All plants have a different osmotic requirement or an optimum nutrient strength. –Rob Smith
As a result of the process of photosynthesis, oxygen (O) is given off by plants. Then, at night, when light isn’t available for photosynthesis, this process is reversed. At night, plants take in oxygen and consume the energy they have stored during the day.
Pests and Diseases
Even though hydroponic gardeners dodge a large number of plant problems by eschewing soil (which is a home to any number of plant enemies), pests and diseases still manage to wreak havoc from time to time. Botrytis, Cladosporium, Fusarium, and Verticillium cover most of the genera of bacteria that can threaten your plants. The insects that can prove annoying include aphids, caterpillars, cutworms, fungus gnats, leaf miners, nematodes, spider mites, thrips, and whiteflies.
A few good ways to prevent infestation and infection are to:
● Always maintain a sanitary growing environment
● Grow naturally selected disease- and pest-resistant plant varieties
● Keep your growing area properly ventilated and at the correct temperatures for your plants
● Keep a close eye on your plants so if a problem does occur, you can act quickly
With insects, sometimes you can pick off and crush any large ones. Or you can try to wash the infected plants with water or a mild soap solution (such as Safer Soap).
If a problem gets out of control, it may be necessary to apply a biological control in the form of a spray. Research which product will work best in your situation. Always follow the instructions on pesticides very closely.
Alternatively, there are a number of control products on the market today that feature a botanical compound or an ingredient that has been synthesized from a plant material.
On botanical compounds as controlling agents:
Over the last few years, researchers from all around the world have started to take a much closer look at any compounds present in the plant kingdom that might hold the answer to our pest and disease control problems. Many companies have even switched from producing synthetic pesticides to copying nature by synthesizing naturally occurring compounds in a laboratory setting. Extracts of willow, cinnamon, grapefruit, garlic, neem, bittersweet, lemon grass, derris, eucalyptus, and tomato have been helpful in controlling diseases and pests. –Dr. Lynette Morgan
The pH of a nutrient solution is a measurement of its relative concentration of positive hydrogen ions. Negative hydroxyl ions are produced by the way systems filter and mix air into the nutrient solution feeding plants. Plants feed by an exchange of ions. As ions are removed from the nutrient solution, pH rises. Therefore, the more ions that are taken up by the plants, the greater the growth. A solution with a pH value of 7.0 contains relatively equal concentrations of hydrogen ions and hydroxyl ions. When the pH is below 7.0, there are more hydrogen ions than hydroxyl ion. Such a solution “acidic.” When the pH is above 7.0, there are fewer hydrogen ions than hydroxyl ions. This means that the solution is “alkaline.”
Test the pH level of your nutrient with a kit consisting of vials and liquid reagents. These kits are available at local chemistry, hydroponic, nursery, garden supplier, or swimming pool supply stores. It is also a good idea to test the pH level of your water before adding any nutrients. If your solution is too alkaline add some acid. Although such conditions rarely occur, sometimes you may have to reduce the level of acidity by making the solution more alkaline. This can be achieved by adding potassium hydroxide (or potash) to the solution in small amounts until it is balanced once again. –Charles E. Musgrove
Plants need to absorb many necessary nutrients from the nutrient solution or–in the case of traditional agriculture–the soil. However, plants can create some of their own food. Plants use the process of photosynthesis to create food for energy. Carbohydrates are produced from carbon dioxide (CO2) and a source of hydrogen (H)–such as water–in chlorophyll-containing plant cells when they are exposed to light. This process results in the production of oxygen (O).
Every now and again, you are sure to run into a problem with your plants. This is just a simple fact of any type of gardening. The key is to act quickly, armed with quality knowledge.
Mineral Deficiency Symptoms
Nitrogen deficiency will cause yellowing of the leaves, especially in the older leaves. The growth of new roots and shoots is stunted. In tomatoes, the stems may take on a purple hue.
A phosphorous deficiency is usually associated with dark green foliage and stunted growth. As in nitrogen deficiency, the stems may appear purple. But since the leaves don’t yellow as they do in nitrogen deficiency, the whole plant can take on a purplish green color.
Iron deficiency results in yellowing between the leaf veins. In contrast to nitrogen deficiency, the yellowing first appears in the younger leaves. After a prolonged absence of iron, the leaves can turn completely white. –Jessica Hankinson
This condition can be caused by environmental factors or disease (usually caused by Fusarium). Nutrient and media temperature can be adjusted to remedy wilt. However, if Fusarium have taken hold, the chances that your plants will survive are slim.
If wilting is due to environmental causes:
Try to spray the plants and roots with cool, clean water to rejuvenate them. If this hasn’t helped them by the next day, try it again. If the plants respond, top-off the nutrient solution and check the pH. If the plants don’t respond to the misting, empty the tank, move it to a shadier spot, and refill with cool, fresh nutrient solution. Don’t reuse the old solution–start with fresh water and nutrients. –Charles E. Musgrove
If wilting is due to a system blockage of nutrient:
I have seen tomato plants that have been so dehydrated due to a nutrient supply blockage that they were lying flat and for all the world looked stone-cold dead. When the nutrient flow resumed and the plants were given the less stressful environment of nighttime, they rebounded so well that I wondered if I had dreamed the previous day’s “disaster.” The moral of this story is to always give plants a chance to revive, even when the situation looks hopeless. –Rob Smith
Plants can be propagated by a number of methods. Growers can let a plant go to seed, collect the seeds, and then start the cycle over again (see germination). Another method is to take stem cuttings, which is also known as cloning (because you are creating an exact copy of the parent plant).
Although this process won’t work with all plants, it is a highly effective technique. Simply cut off a side shoot or the top of the main shoot just below a growth node. Make sure that there are at least two growth nodes above the cut. Remove any of the lower leaves near the base of the new plant. This cutting can then be rooted by placing it in water or in a propagation medium (perlite works well) that is kept moist. The use of some rooting hormone can help your chances of success.
Remove any discolored, insect-eaten, or otherwise sick-looking leaves from plants. Picking off some outer leaves or cutting the top off a plant can help it grow fuller. Use sharp scissors to prune your plants. Sometimes you will want to prune a plant to focus its energy on the remaining shoots. Pruning is an art and should be performed with care. Damaged or dying roots may also need to be pruned from time to time.
Never use soil during any aspect of hydroponics. If you ever move a plant from a soil-based situation to hydroponics, remove all traces of soil or potting mix from the roots. Soil holds lots of microbes and other organisms and materials that love to grow in and contaminate your hydroponic system. Some of these will actually parasitize your plant and slow its growth. This is another advantage of hydroponic growing: The plant can get on with growing without having to support a myriad of other organisms as happens in conventional soil growing. –Rob Smith
Different plants have different germination and growing temperatures. Always make sure that you check each plant’s growing requirements–especially minimum and maximum temperature levels. Keep in mind that specific varieties of plants may have different requirements.
Because the water supply is the source of life for your plants, quality is important. All plants rely on their ability to uptake water freely. Between 80 and 98 percent of this uptake is required for transpiration (loosely compared to perspiration in animals), which allows the plant to produce and somewhat control its immediate microclimate. Plants also need clean, uncontaminated water to
produce their own healthy food supply. –Rob Smith
The water you use in your hydroponic system needs to be pure. It is always a good idea to test your water source before adding nutrients so you aren’t adding an element that is already present. In small systems, it would be wise to use distilled water.
If you are starting a larger hydroponic operation, it would be a good idea to have a water analysis completed. Factors such as sodium chloride (NaCl, or salt) content and hardness will be of great use to growers. Also, groundwater can have elements normally not present in conditioned water. A key piece of advice: Get to know your water!
Growing Tips From the Experts
Rooting a Cutting:
● have everything ready first then take your cuttings and plant them right away
● for best results, take cuttings first thing in the morning
● use only healthy actively growing stock plants with soft green stems (woody stem cuttings do not root fast!!!)
● for green stem (softwood) cuttings use a straight clean cut; for yellow or brown stem cuttings use a slanted cut
● remove any leaves or branches that would be below the soil line (snip off leaf stem, leaving a 1/4″ stub)
● dip cutting into “Roots” or other hormone products
● after planting, trickle a few drop of water down the stem to settle the soil mix around the stem
To Root in Potting Soil or Soiless Mixes:
● fill containers with potting mix
● water well with room temperature water with “Nutri-Boost” added (“Nutri-Boost” is a vitamin mix; add 7 drops per litre or quart of water)
● it is always a good idea to have “No-Damp” nearby in case you notice any signs of wilting; if this occurs, use the recommended application rate of l0m. “No-Damp” to 1 litre of water and spray generously
● now take your cuttings, dip them into a rooting hormone and plant them right away
To Root in Rockwool Cubes:
● rinse cubes in lukewarm pH balanced water
● water cubes with “Nutri-Boost” solution as described above
● plant the cutting 3/4″ of the way into the cube
More Helpful Hints:
● root cuttings under moderate light (flourescent light) at 70 – 75°F
● if you use a clear cover, remove twice a day and wipe any condensation off the cover and replace ● use only water and “Nutri-boost” solution until cuttings show signs of new growth at tips then feed with 1/2 strength fertilizer
Hydroponic Nutrient Manipulation and Modification Techniques or “Playing with your food”
Some gardeners are ignoring their mother’s advice and modifying their fertilizer mixes. The fact is, the soil-less mixes, lava rock, rockwool, etc. hold little or no food compared to garden dirt, so any change in fertilizer strength or quality is noticed by the plant almost immediately.
This is why gardeners use different fertilizers for different stages of growth, giving the plant just what it needs for today’s “Work”. Here are some other tips on changing your fertilizer mix for special circumstances.
We match food strength to growing conditions in the garden, and to the health and activity of the plant.
Weak fertilizer for:
● newly rooted cuttings
● plants in low light conditions
● plants in hot gardens (over 90°F or 33°C)
● plants under stress – disease, bugs, etc.
● plants in transition between stages of growth
● plants in poor growing conditions – crowded, root-bound, poor air movement, etc.
Regular Strength Fertilizer for:
● healthy plants in active growth
● good light levels, temperature and air movement
Strong Fertilizers for:
● natural spurts of growth in crop plants
● plants in very good growing conditions – very high light levels; precise, consistent temperatures; major air movement through plants; excellent exhaust and intake fans; huge quantities of C02 delivered efficiently to the garden; regular growth hormone treatments (to help the plant take up stronger foods)
Note: Increase food strength gradually – watch for black leaf tips!
Food Formulas – We modify fertilizers by changing the quantity of individual nutrients for special circumstances.
Low Nitrogen Fertilizers:
● to avoid “stretching” (long thin stems) of plants between stages of growth.
● a good example would be a chrysanthemum grower who has shortened the day length to make the plants start their flower cycle; he would use a full strength fertilizer with Nitrogen only (1/2 strength or less) to keep the plants compact until the flower buds form.
● return to regular Nitrogen levels once your plants have actually begun their next growth stage.
● this trick works especially well with our “B” and “C” fertilizers.
You can see that gardeners start by examining the conditions in the garden and the “job” of their plant, then decide what strength and quality to mix their fertilizers.
So What’s the Deal with Pesticides?
Well, they suck! However, sometimes they are necessary to save your valuable crop. The “new” trend is to use pesticides only as a last resort. Your object is to control your pests and you might even get lucky and wipe them out.
Start with a healthy plant! It’s much less likely to develop problems than a plant under stress. Bugs seem to sense a hurting plant, much like a pack of wolves will prey on an injured or tired animal. That’s where our Predators come In. Just wonderful little things. They are moderately priced and they do all the work for you. When the bad guys are all gone, (ie. no more food), they either pack their bags and leave, or eat each other down to the last one. Predators are carnivores (eat meat) not herbivores (vegetarians), therefore no worries about damage from them.
Predators have been used since before the “Dead Sea” was even sick. It’s only since First World War France, where pesticides and rodenticides were first used in the trenches to relieve troops of overwhelming infestations that we have changed our thinking. We’ve been poisoning our land, our water, and ourselves ever since. Some treatments are much safer than others. Pokon and Safers Soap are a good organic way to go, plus we can get you Predators within a day or two. This old/new topic is called “Integrated Pest Management”, or I.P.M. for short.
Avoiding Plant Diseases
Watching healthy plants get sick and die is a very depressing sight to a gardener. Plant diseases are always out there, waiting to attack your garden. While sonic diseases are easily treated, other more serious diseases will require repeat treatments to handle. Some diseases are so serious (tobacco mosaic virus for example), that the plant is doomed. Plant diseases can seriously lower crop production, even if the sick plants recover. Lets keep diseases out of our gardens! Here’s how:
Good Growing Conditions and Practices:
The best defence against plant disease is to keep your plants healthy and actively growing, by creating good conditions in your garden.
Attention to temperature, air movement and air change, proper spacing of plants, consistent growing conditions – all these practices ensure healthy, stress-free plants that can resist bugs and disease well. Often, bugs and disease will attack a weak plant in your garden and build up armies to invade the rest of your healthy plants!
Use Healthy Plant Stock
● a cutting from a sick plant will carry on the disease in the new plant.
● some varieties of a plant will have greater natural resistance to disease than their “weak sisters”; if possible, grow only varieties that have known disease resistance.
Keep Tools, Hands and Clothing Clean
● diseases, pests and insect eggs can travel to new host plants
● during pruning, transplanting and handling; wash your hands after handling diseased plants before you touch a healthy one
● clean tools and knives well after use
● keep garden clear of dead leaves
Sterilize Garden or other Grow Mediums (a Medium is what your roots are growing in)
● this is especially important when using garden dirt from the backyard in a container indoors or when using recycled rockwool or lava rock for new crops
● the soil-less potting mixes and new rockwool are considered clean already – no further treatment is needed
Use R/O Water or Distilled
● if you are concerned about the possibility of disease in your water, there are a couple of simple methods to treat water and kill disease before you infect your garden:
Chlorine Bleach (1/4 cup for 30 gallons)
❍ add to water and stir well
❍ add fertilizer to water after treating with bleach
❍ use air pump and air stone to drive off bleach and keep water bubbly
Hydrogen Peroxide (35%) (1 tablespoon for 10 gallons)
❍ this product is actually water with extra oxygen, and the active oxygen will kill disease in the water
❍ add to water
❍ stir well, then add fertilizer
Note: Peroxide helps plants to take up food easier and quicker, so this treatment has an extra benefit to the garden.
Watch your garden for problems and treat them promptly! You may eliminate the disease entirely, before it gains a foothold in your garden.
Treating Fungus and Bacteria in Your Garden
Seedlings and Newly Rooted Cuttings
● treat with No-Damp or other mild fungicide
● be sure roots are already wet before root-drench treatment: No-Damp contains alcohol that could damage dry roots or unrooted cuttings
● treat plants once a week until plants recover
Vigorous Plants – Green Growth (no flowers or crop on plant)
● spray top-growth well with Safers Garden Fungicide
● wet all leaves until liquid runs off leaves
” Caution ” – Do not spray plants with flowers or crop on them; you will definitely burn your crop!
● treat your plants once a week – the best time to spray is late in the day, so the plants can dry in the dark; avoid spraying in strong light.
Flowering or Crop Plants
● treat plants by hand-watering Benomyl fungicide into the roots
” Caution ” – Never spray a flowering plant with fungicide; it could damage the flower or crop!
● water enough Benomyl solution into the roots to drench the entire root system
● treat the plants when the roots are already wet from feeding or watering, and when they won’t be watered again for at least a few hours
● treat once a week
Hints on Treating Plants for Disease
● avoid high temperature and strong fertilizers until plants recover
● disease can become tolerant of a fungicide if used many times; after you have used one product three or four times in a row, switch to another suitable product and attack the disease with a new weapon.
Safers Garden Fungicide is a sulphur based product only for spraying Green Growth.
Do not use Safers Garden Fungicide for crop plants!
Lighting Tips Photosynthesis
Photosynthesis is the process by which plants use light energy to collect carbon dioxide from the atmosphere and convert it to chemical energy in the form of sugar. The products of photosynthesis serve to nourish the plant and enable it to release free oxygen. Plants use only the spectrum of light that is visible to the human eye. Although the light appears white, it is actually a mixture of all the colours of the rainbow. Pigments, which are the light harvesting units of the plants, absorb certain colours of the spectrum and reflect the rest. Chlorophyll, the main pigment used in photosynthesis, absorbs light in the violet and blue wavelengths as well as in the red, leaving green the colour it reflects, and the plant colour we see. Photosynthesis can also occur indoors, providing the artificial light source used supplies the necessary spectrum and intensity.
Wide spectrum fluorescent, metal halide, and high pressure sodium are the types of lights most widely used for indoor growing. All of these lights require a ballast to operate and come in a variety of sizes and wattage’s.
Homegrown provides a wide range of grow lights that provide the necessary spectrum and intensity to suit plants’ needs.
Sunmaster line of Metal Halide Lamps was developed specifically for plant growth by closely matching the spectrum of natural sunlight.
Light is the most growth influencing factor!
● mylar reflects with up to 95% efficiency
● flat white paint reflects with up to 80% efficiency
● never use tinfoil for reflection it creates “hot Spots”
● use air cooled reflectors when heat build-up is a problem
● 15 minute time delays for halides prevent “hot starts”
● low pressure sodium lights greatly increase intensity for pennies a day
● light movers increase growth by up to 40%
● halide “super”bulbs increase intensity but not your hydro bill
● 430 watt Son Agro sodiums supply 30 extra watts of blue light
● wear sunglasses when working close to an H.I.D. bulb
● if your light fails, don’t try to fix it yourself, contact a qualified expert
Before high intensity discharge light came along, indoor growers depended mainly on fluorescent lights for best results. They are inexpensive, reasonably energy efficient, and most emit a wide enough spectrum of light for plant growth. There is a wide range of fluorescent bulbs or “tubes” available, and are categorized by wattage, length, and colour of spectrum range. Indoor growers should look for the type specifically made for plants such as the vita-Lite* or Ultralume 5000*.
The fixtures for these lamps are usually complete with lamp holders, reflector, and built-in ballast. Since the introduction of H.I.D. lights, fluorescent now are mainly used for propagation and early vegetative growth. The 20 watt,24 INCH, and 40 watt, 48 inch, are the most common. The more intense and energy efficient H.I.D.’s are now the choice for maturing high-light plants and vegetables indoors.
High Intensity Discharge (H.I.D.) Grow Lights
Metal halide lights were created to provide a spectrum as close as possible to that of the natural sunlight. This coupled with their intensity and energy efficiency, makes them ideal for indoor gardening. The bulbs range in size from 100 watt to 1000 watt with 400 watt and 1000 watt most popular.
An abundance of blue light emitted by metal halide makes them the best light for propagation and vegetative growth, promoting short internodal length High Pressure Sodium lights do not emit as broad a spectrum as Metal Halides lights, but have many advantages, especially when used in conjunction with halide. Sodiums last longer, and burn brighter, but are still more energy efficient.
More yellow/red colour in the spectrum and less blue promotes a higher flower-to-leaf ratio in flowering plants. H.P.S. lights are widely used in commercial greenhouses, where natural sunlight provides sufficient blue. A combination of the two lights provides the best balanced for indoor growroom, especially when used with a light mover. 430 Watt Son Agro H.P.S. bulbs which supply 30 extra watts than regular ones are now available. This extra light in the blue end of the spectrum is great news for indoor growers. If you are planing a “single lamp” growroom, you can still get the benefits of both halide and sodium light. High pressure sodium “conversion bulbs”, specially made to operate with M.H. ballasts, are available in 400 watt and 1000 watt models. The bulbs can easily be interchanged as needed, using the same ballast and fixture. The size of the light you will need will depend on the size of the growing area, and the type of plants you wish to grow.
High-light plants such as herbs and vegetables will require between 20 and 60 watts of light per square foot of growing space. A 400 watt metal halide in a three foot by three foot area will provide 45 watts per square foot, compared to 25 watts per square foot in five foot by five foot growroom. A 1000 watt metal halide in a five foot by five foot area will provide 40 watts per sq.ft., compared to 20 watts per square foot in a seven by seven foot growroom.
Proper reflectors, light movers, and reflective material on walls greatly increases intensity and efficiency of these lights.
Most high intensity lights can be run with either 120 volt (standard house current), or 240 volt (e.g. used for electric dryer).
Electricity cost would be the same but the latter would draw half the amps allowing the grower to run twice as many lamps on the same electrical circuit.
Light timers are available for either voltage but always check to see that the amperage rating on the timer exceeds that of the light or lights.
Care should always be taken when installing and using H.I.D. lights. Remote ballasts should be placed safely out of the way where they can’t be knocked over or splashed with water. Never keep your ballast on the floor in case it gets wet. Installing the fixture and reflector is simple. Locate a stud in the ceiling near the centre of the grow area. Screw a metal hook capable of holding 40 to 50 pounds into the stud and test it’s strength. Attach a 4′ to 6′ length of lightweight link chain to the hook or hooks on top of the fixture and hang the fixture from the ceiling hook at the desired height. The link chain allows you to easily raise and lower the light when necessary. Hold the lamp near the base and firmly, but gently, screw the bulb into the socket. Connect the timer to the power source, plug the power cord from the ballast into the timer which should be set in the “on” position. It may take up to 30 seconds for the bulb to ignite and up to five minutes to reach full brightness. As the lamp ignite, they tend to flicker and change colour for several minutes. This is quite normal, especially with halide bulbs, which may appear to change colour slightly during normal use. If the lamp does not ignite after 30 or 40 seconds, unplug it. After the power has been disconnected, check
● that the bulb is screwed in all the way
● that the timer is set on the “on” position
● that all plugs or electrical connections are O.K.
NOTE: Do Not Open The Ballast Enclosure To Check Wiring Yourself! H.I.D. capacitors can hold a charge even after the ballast is unplugged! Once these points have been checked, try the light again.
Once a metal halide lamp is turned off it requires a 15 to 20 minute “cool down” period before it can be re-started. If ample cooling time is not allowed, a “hot start” occurs, and too many “hot starts” can seriously affect the intensity and longevity of the bulb. For best results, replace halide bulbs after one year of steady use. High pressure sodium lamps require only 2 to 3 minute “cool down” period and need only be replaced every two to three years.
The most efficient way to use high intensity lights is to have them moving within the growroom.
There are many advantages to this, and a number of different ways it can be done. Moving the lights will eliminate plants tendency to grow toward the light source and provide light to areas which otherwise may be shaded. Since the light is moving, it can pass quite close to the plants without burning the leaves. Moving lights cover more area than stationary ones, reducing electricity costs and ensuring more even growth.
More intensity also allows plants to be placed much closer together, greatly increasing yield and quality. The size and shape of your room will determine the type of light mover that will best suite your needs.
Lineal movers carry the light fixture slowly along a track and back again during the light cycle. Most are six feet long,support a single lamp, and are recommended when the growing area is long and narrow.
Circular movers are best when the length and width of the room are similar. They are designed to carry either one,two,or three lights, in a 360 degree circle,ideally lighting a ten by ten foot area. This diameter can be reduced but rarely extended.
Two arm and three arm movers are most popular,with the latter supplying much more light per square foot. More intensity means plants can be placed much closer together,greatly increasing yields.
Advantages of using light movers:
● more even growth over a larger area
● lamps may be placed closer to crop
● increase growth by 40%
● stronger plant stems
● counteract leaf shading
● circular movers can move up to 3 lamps
● 1 or 2 meter linear track support single lamps, extension kits are used for additional lamps
Benefits of Hydroponic food production.
Hydroponics and Environmental & Health issues
● Pesticide free products through biological pest control
● Nutrient solutions may be re-used in other areas such as potted plants and turf management.
● Growing mediums can be re-used and recycled.
● Hydroponic systems use little or no growing medium.
● More intense cropping technique requires less space.
● Non-arable land may easily be facilitated.
● Year round crop production in Canada reduces transportation of imports and therefore associated solution e.g. fossil fuels.
● Promotes an overall awareness of our environment.
● Closed recirculating systems allow the grower control of the nutrient solution and therefore exactly what nutrients the plants receive.
● Varying nutrient formulas to suit different plants at different stages.
● Regular nutrient testing ensures all elements are present in their desired concentrations. Unwanted build ups of undesirable nutrient concentrations, such as nitrites, can be avoided.
● Hydroponic plants are more pest resistant.
● Control over environmental factors translates to a nutritionally superior, vegetable product.
● Vine ripened, Canadian grown produce eliminates consumption of artificial ripening agents and pesticides used on imported produce.
● Vine ripened, Canadian grown produce tastes superior and is nutritionally sound.
Hydroponics and Economical and Social issues
● Canadian business stimulates Canadian economy for growers, manufacturers of their supplies, as well as distribution, wholesale and retail outlets.
● Opens up positions for job training and employment.
● Satisfies consumer demand.
click to the next article-Benefits of Hydroponic food production