Helpful Information About Outdoor Hydroponics
Outdoor hydroponics is certainly a growing trend for many good reasons. This practical and effective method of growing plants is done without any soil, using only water and nutrient solutions. Terrestrial plants are able to be grown either in a nutrient solution or an inert medium including gravel, perlite, coconut husk or mineral wool, with their roots.
Hydroponics vs Soilless Culture
The distinction between soilless culture of plants and outdoor hydroponics is often confused. Hydroponics is a much smaller term than the broad coverage of soilless culture. When examining soilless culture, the only stipulation is that no solid with silt or clay be used. Interestingly, sand is allowed however, technically speaking, sand is a type of soil.
While billions of plants in containers are produced every year including trees, forest seedlings, shrubs, bedding plants, vegetable seedlings, vines and perennials, they are in a soilless medium but not considered hydroponics. Even some plants that are grown in peat bags in greenhouses are often referred to as hydroponics however the medium actually provides some nutrients to the plant so the term is used incorrectly.
Advantages Of Outdoor Hydroponics
- No soil is required.
- Lower water costs because the water remains in the system and is reused.
- Lower nutrition costs because you are able to control nutrient levels.
- No pollution from the nutrients is released due to the controlled system.
- High and very consistent yields.
- Low risk of disease and pests.
There are three primary techniques that can be used in outdoor hydroponics including aeroponics, continuous flow solution culture and sand culture.
- Aeroponics – In this system, the roots are continuously kept in an environment that is saturated with a nutrient solution by using aerosol or a mist. No substrate is required and the plant's roots are suspended in a growth chamber where they are periodically moistened. The main advantage is exceptional aeration. Aeroponics is successful for micro-greens, leaf crops, tomato production, seed potato production, seed germination and propagation.
- Continuous Flow Solution Culture – In this technique, the solution of nutrients constantly passes the roots. Adjustments can easily be made and the roots are always supplied oxygen. A solution of water and nutrients is constantly recirculated past the roots by using a thick, watertight root mat.
- Static Solution Culture – The most popular method of outdoor hydroponics is static solution culture. You can use plastic buckets, containers or even mason jars and the plants are grown in them. The solution is usually aerated however, if you choose to use unaerated then the solution is always kept low and at a level where the roots fall above the solution so they are provided with adequate oxygen.
Types Of Medium
One of the hardest decisions that has to be made with outdoor hydroponics is which medium to use because specific ones are required for different growing techniques.
- Diahydro – The fossilized remains of this material create a sedimentary rock medium. It is very high in silica which strengthens the cell walls in plants.
- Expanded Clay – These baked clay pellets have no nutritional value. The clay is formed and fired which causes the pellets to expand and become porous. They do not compact over any length of time and they are very light weight. Expanded clay is an ideal medium because it can easily be cleaned and sterilized.
- Perlite – This volcanic rock is extremely lightweight. It is quite similar to vermiculite but holds less water and more air.
- Vermiculite – These light pebbles are created from super-heating the mineral. It holds water and naturally wicks moisture so if your plant is not receiving enough oxygen, adding a bit of vermiculite will help solve your problem.
- Rock Wood – This is the most popular medium used in hydroponics. It is ideal for recirculating systems and free drainage. After use, it can be recycled either into new rockwool or bricks because it is completely natural.