A brief overview of Hydroponic gardening and its history.
Centuries before the time of Christ, Egyptian records show that plants were being grown in the Nile without the use of soil and Marco Polo describes floating gardens in China in the thirteenth century. Over the past one hundred and fifty years, a great deal of research has taken place into soil-less cultivation, particularly during and after the Second World War when there was a need to produce food for military personnel stationed in areas where it would be otherwise impossible to raise fresh produce. Nowadays, in so-called developed countries, a great many plants are produced hydroponically. In Europe, for instance, around 80% of tomatoes and 90% of cucumbers come from hydroponic systems, as does much of the huge production of flowers in Holland.
Nutrients and Water
There are many plant nutrients available and the choice can be confusing. Most are produced on a simple NPK formulation some are produced using a more complex formulation and or have built in growth enhancers. Friendly recommendation or experienced in-store advice should steer you in the right direction so please tell us your needs and we will happily advise you on the suitable choice.
Water quality can make a considerable difference to the quality of the food supplied to your favourite plants, and the first and most important factor of choosing your nutrient is ” are you in a Hard or Soft water area? ” ..this is important as Hydroponic nutrients are produced in either Hard or Soft water formulations, which will partially adjust your waters pH level to suit. Even so, some pH adjustment will still be necessary with the aid of pH Up & Down acids.
A quick ‘in house’ test to see if you are in a Hard water area is to look in your kettle to see if there is much limescale at the bottom!..if there is, then it is likely that you are in a Hard water area. We recommend asking your local grow shop or contacting your local water board just to be sure.
To create the perfect nutrient mix, you may wish to consider Reverse Osmosis which will strip 99.9% of impurities from your water supply. Please contact us for more information if required.
What is Hydroponics?
When a plant is grown in soil, it will mature according to the quality of soil, the frequency of watering and feeding and the amount of light and heat it receives. Other aspects, such as pest and disease control, may then be considered where applicable, along with individual requirements for the type of plant. Since soil already contains nutritional minerals, plants grown in soil can only be fed nutrients or fertilizers at a rate that will not leave a build up of nutrient salts that harm the growing process.
When a plant is grown Hydroponically, it simply means that the plant is grown in an inert medium, that is to say in a medium that holds no nutritional value of its own, to which nutrition may be added at enhanced but acceptable levels. In this way, it is possible to influence the growth of the plant so that it realizes its maximum potential. Plants require water, light, oxygen and nutrition. The Hydroponic gardener is not forcing the plant to do anything un-natural, he is just providing these factors in a growing environment that provides them at maximum possible levels.
Partial article Copyright L.Elswood, G.Gunstone & T.Jarvis 2001
Successful Propagation and Cloning
A. Starting from Seed:
- Soak RockWool SBS Tray in lukewarm water or a weak and slightly acidic nutrient solution. We highly recommend FORMULEX as a conditioning solution for RockWool as it will stabilise the pH and supply a full profile of mineral nutrition to the young plant. Use it at the weakest strength mentioned in the instructions. Allow plenty of time for RockWool cubes to take up water. Stand it to drain.
- Insert seeds carefully into the holes marked out on top of the cubes. Don’t push them in too far, just enough to hide seeds. A few strands of RockWool should be teased over the hole to ensure that seeds are covered.
- Place RockWool SBS Tray in a warm place. Light is unimportant until the seedlings begin to emerge but MUST be supplied as soon as they do Ideal germination temperatures for most species are in the range 20 – 25 o C. These temperatures should be maintained as constantly as possible during the germination period. Check the moisture level of the RockWool EVERY day. If you just squeeze a corner of a cube, water should come to the surface. If it does not then you should give the whole tray a light sprinkle of lukewarm water.The biggest mistake with RockWool is to keep it too wet and this usually occurs through poor drainage. NEVER let your RockWool stand in a puddle of water, always allow free drainage underneath the tray.
- Once your seedlings begin to appear you will need to give them plenty of light, a warm sunny windowsill might do but a greenhouse or artificial lights will be best. Fluorescents are very suitable for small seedlings or clones. It is still important to maintain temperatures in the mid twenties for as much of the day as possible. Keep checking your RockWool cubes for signs of drying out.
- Once your seedlings begin to show roots at the bottom of the RockWool cubes it is time to think about planting them out. Just lift the little cubes carefully from the tray Your new seedlings are now ready to plant into soil in the normal way OR to be cultivated further in RockWool. More information about RockWool can be found further on.
B. Starting from Cuttings (Clones):
If you already have access to healthy plants that display desirable characteristics it is possible to clone new plants from them. These new plants will be genetically identical to the stock plant and, provided that the environmental conditions are constant, the new plants should perform exactly as their parent did.
- Soak RockWool SBS Tray in a weak acidic nutrient solution (pH 5 / 1.0 mS). FORMULEX is ideal for this. While the RockWool is soaking, you can be selecting material for cuttings. Most species are propagated best from softwood tips. Selected material should show signs of healthy vigorous growth. Stems should be thick and firm and foliage should be dark green.
- Remove selected piece from mother plant with sharp scissors, taking care to cut plant at least 10 mm below the point where the final cut will be made. Final cut should be made with a sterile scalpel or clean sharp razor blade just below a node or leaf junction. A diagonal cut is preferred as it allows more plant tissue to come into contact with the rooting compound.
The rooting compound we recommend highly is Clonex Rooting Gel. Pour a small amount of Clonex into a small container for immediate use. Do not dip cut tissue into the container.
Immediately dip the cut tissue into CLONEX, ensuring that all cut surfaces are well covered with CLONEX. Wipe off surplus CLONEX against the side of the small container. Do not return any of the unused Clonex back to the original container as this might contaminate the remaining gel.
Insert cutting into hole in top of RockWool cube. It is very important not to push it in too far, just enough to support it in an upright position.
Copyright Growth Technology
Nutrient Film Technique systems are some of the most productive available, and they are often the chosen method of commercial growing. Plants are grown in an inert medium (usually RockWool cubes) and placed into a light-tight and shallow channel. Nutrient solution is continuously circulated, flowing over the roots up to 24 hours per day. The name of this growing method was so coined in order to stress that the depth of the liquid flowing past the roots should be very shallow in order to ensure that sufficient oxygen is supplied. This growing technique is generally favored by gardeners that wish to grow multiples of small to medium sized plants that will yield heavier than their size would usually determine.
Often these types of systems are called Ebb & Flood. The plants are usually grown in pots with their roots supported by an inert medium ( usually expanded clay pebbles) the pots sit in a plastic tray which in turn sits above a reservoir filled with nutrient solution.
A pump in the reservoir is connected to the bottom of the tray. When the pump turns on, the tray fills with water. When the water level reaches a pre-determined height, through the use of the overflow fitting, the water falls back into the reservoir. When the pump turns off, the water runs back down through the pump into the reservoir.
Most growers choose to control irrigation with a timer. A typical schedule would involve several short one-hour water cycles per day, but the duration and frequencies of watering cycles varies from one system to another and is dependent on the crop, the plant size and environmental conditions.
This growing technique is generally favored by gardeners that wish to grow high density medium sized plants, while providing a well oxygenated root system.
Drip systems are the most widely used Hydroponic systems in the world. They are commonly used in commercial facilities for growing long term crops like tomatoes and peppers. Drip systems provide plenty of aeration (more than ebb and flow) because plant roots are never totally submerged, but are never allowed to dry out.
Drip systems operate very simply. A pump has tubing connected to it which then branches off to smaller tubes feeding many plants. Nutrient solution is dripped onto the base of each plant where it then trickles down through the grow media (inert or soil based) and into the roots and finally drains into the reservoir where it is re-used, unless ‘Run to waste’ is employed ( dosing a precise amount of nutrient which does not re-circulate).
This growing technique is generally favored by gardeners that wish to grow small to large sized plants, while providing a precise and controlled feeding program.
The hydroponic method of plant production by means of suspending the plant roots in a solution of nutrient rich, oxygenated water. Traditional methods favour the use of plastic buckets with the plant contained in a net pot suspended from the centre of the lid and the roots suspended in the nutrient solution. An airpump or aerator is placed in the bucket or pod, which delivers a constant and very high level of oxygen, leading to explosive root production.
This growing technique is generally favored by gardeners that wish to grow medium to large sized plants.
Aeroponics is an exciting improvement on hydroponics that has been shown to greatly increase all aspects of plant growth, especially where Propagation is concerned.
The roots of the growing plants are suspended in the air in a suitable channel, where they are misted by high pressure sprayers. The sprayers break the nutrient into small particles and saturate the roots. The levels of oxygen in the water are kept high by the constant circulation of the water; this leads to explosive root production and enhances every aspect of plant growth. The nutrient run-off is then returned to the tank for re-circulation.
This growing technique is generally favored by gardeners that wish to grow small to medium sized plants or produce exceptionally healthy Clones where Aeroponic Propagators are concerned.
Aside from Propagators.. please be aware that if you are in a Hard Water area, an Aeroponic system may require extra vigilance and maintenance.