Aeroponics Systems: Ultimate Guide
Aeroponics as a modern method of gardening has been steadily gaining popularity among city dwellers and busy professionals. Who could blame them? This method is the perfect synchronous of convenience and aesthetic appeal. It does demand a lot of time and resources for plant cultivation. At the same time, it serves as a mental and physical therapy for people who are constantly exposed to the hustle and bustle of city life.
What exactly is aeroponics and why is it making a buzz?
Aeroponics is a modern method of growing plants without the use of any medium, such as soil in conventional gardening and water in hydroponics and aquaponics. The plant grows by absorbing nutrients from a special solution that can be directly sprayed or misted to its roots with the help of special equipment that automatically releases the nutrient-rich solution at specific intervals.
The process is well-favored by city dwellers and people living in small spaces—usually confined—due to its low maintenance and aesthetic appeal. Growing plants with their roots and crown (upper body of the plant) suspended in the air is undeniably eye-catching, after all.
Experiments in aeroponics date back to the early 1900s, but it was not until the 1940s when the system had seen its inclusion in horticulture or the science of growing plants as a systematic method of plant cultivation. Today, aeroponics is considered a “must” for indoor farming, especially when it comes to vertical gardening.
Contrary to popular belief, this system is convenient and practical for novices and busy professionals as plants cultivated through this method tend to grow healthier and faster as already proven by NASA in their experiment in 1997.
The quality of yields might differ depending on the quality of air and the level of control applied to misting. However, urban environments should not be a problem for as long as the method is applied indoors and the water used is properly processed.
How Does Aeroponics Work?
The plants are suspended in an open space to allow their roots to grow outwards, which exposes them to the sprayer or mister installed below, and the crown upwards, which exposes it to light source. Many specialty stores now sell seedlings that have already been planted and are ready for hanging. The possibility of loss and stunted growth is minimized this way as the initial stages require close monitoring and accurate solution computation based on the plant’s nutrient requirements.
Nevertheless, most horticulturists and hobbyists prefer to plant seeds in foams until the roots sprout and dangle. The foam used is a closed-cell type, which is as equally absorbent as your common household foam typically used in the kitchen and the bedroom, but holds moist longer due to its higher density. The foam is then inserted in hanging pots or customized boards that can either be installed against the wall, suspended from the ceiling using durable strings, or set over a table frame.
Trellising can also be done for certain vines and larger crops like vegetables and fruit-bearing plants. To save space and keep the garden neat-looking, many plantations utilize thick hollow tubes and special columns where plants are inserted, allowing their crowns to absorb sunlight while keeping the roots dangling from the inside. The nutrient absorption rate of the plants in this design is also higher compared to open-air misting. Moreover, the environment is kept dry, preventing the growth of molds and spores on exposed surfaces in the process, since the mist is confined within the tubes.
The only problem with this design is that it requires higher costing as implied by the number of misters corresponding to the number of tubes installed. Hence, the design is usually preferred only for commercial plant cultivation.
Aside from the design, the success of yields also largely depends on the nutrient-rich solution sprayed to the plants. Mixing the solution is normally not the problem as many stores already sell plant-specific ready-to-use mixtures. Where gardeners normally get it wrong is in the amount of solution sprayed to the plants and the type of water used for mixing.
Saturation is common for manual spraying, especially when the specific requirement of the plant has not been researched. The use of hard water when mixing can also result to lower nutrient absorption. This is especially true for rustic areas where the garden water sometimes directly comes from natural sources and wells.
Hard water is rich in calcium carbonate that is deemed unwise for gardening. As such, it cannot be processed well by plants, same as how humans cannot process salt very well, resulting to various health complications. Unfortunately, entry-level water filters are insufficient in removing this mineral from hard water.
Many novices also commit the mistake of “over-nourishing” their plants. Due to the plants’ sensitivity to hard water, some people use alkaline water and purified water instead, which also yield poor crops. Plants grow better in a slightly acidic environment, so distilled water that has lower ph level might be a better choice.
Lower ph levels indicate acidity while higher ph levels indicate alkali.
Aeroponics system uses osmosis in nourishing plants. It is a process where the nutrient-rich solution is released through spray or mist, ready for the roots and stems to absorb. The rest of the solution is absorbed by the closed-cell foam, which does not evaporate easily as compared to when it is absorbed by soil. Thus, the plants have more time to absorb all the nutrients before they get lost through evaporation.
There are different types of aeroponics systems, although aeroponics itself is also sometimes referred to as a subtype of hydroponics due to the absence of soil and its reliance on water-mix solution. It is usually classified as low-pressure type, high-pressure type and commercial type.
The differences between the three lie on the size of water droplets produced by the misters and the extra equipment used to control the closed environment.
The low-pressure type uses low-pressure pumps that produce larger water droplets. These droplets take longer to absorb, so there is higher chance of the nutrients getting lost in the air. Many amateur gardeners use typical misters for this set-up, which is just fine for as long as the more sensitive high-value crops are not used.
This type of aeroponics is most suitable for novices and ornamental plants. Its set-up and maintenance costs are low, but it is a bit messier. Adding a reservoir system to catch drips from the roots and to recycle the nutrient-rich solution might solve this dilemma, but this might also result to a new problem with impurities and pathogens falling down the recycled water.
On the other hand, the high-pressure type uses higher-pressure pumps that produce finer droplets that are perfect for aeroponics. The absorption rate of nutrients is improved this way, especially when a 20-millimeter mist head is used.
This is the best choice for experienced gardeners and horticulturists when cultivating high-value crops and sensitive ornamental plants due to its efficiency in releasing mist. However, it is way pricier than its low-pressure counterpart. Air and water purification features are normally added to this type. A pressurized dispenser and nutrient sterilizer may also be added if desired.
Lastly, the commercial type is utilized for the commercial plant cultivation of vegetables and fruits. The pumps used are all high-pressured, but they normally come with advanced biological systems geared to monitor plant maturity and match it with adjusted water-nutrient ratio, temperature, cooling and heating features, disease control mechanism and other technical requirements. Ultrasonic foggers may also be used to atomize droplets, making them finer and easier to absorb.
What Are the Benefits of Aeroponics?
Removing the need for soil in aeroponics is akin to freeing the plant from growth restrictions. As the roots and crown are now all exposed to air leading to better absorption of carbon dioxide, the plant maturity also becomes faster by at least three-folds. The exposure of the root zone to more oxygen may also improve the nutrient density in the produce.
Another surprising benefit of aeroponics system is the significant increase in yield. A study conducted in the University of Arizona to test how it can improve farming concluded that burdock herbs cultivated through the system yielded 10x more than those cultivated in mineral—rich soil.
An older study in Italy conducted in 1991 also found out that tomatoes grown with their roots suspended in the air can produce fruits up to four times per year. That is 200% to 400% more than what farm-produced tomatoes can yield.
In terms of maintenance, aeroponics is considered cost-efficient as most of the big expenses are usually present only during set-up. This is especially true for the mister and the holding medium, which can be used over and over again. More complex types require higher costing, nonetheless.
Many novice urban gardeners prefer the aeroponics system as plants grow well even with limited space and limited exposure to sunlight. The absence of soil also minimizes the possibility of diseases affecting the plant and of pests damaging the roots and leaves.
Finally, the use of closed-cell foam rather than soil greatly reduces loss of water and nutrients to evaporation.
What Are the Disadvantages of Aeroponics?
Just like any other cultivation method, this one is not without any disadvantages. The benefits outweigh the disadvantages, nevertheless, from a general perspective.
The reliance of aeroponics on electrical power to produce mist at programmed intervals is the most common complaint. It is not sustainable for many gardeners, but busy professionals may not have much choice anyway.
There might also be a need for the installation of artificial lighting if the location lacks natural sunlight, like in the case of many apartments in the city.
Cleaning the mist nozzles to prevent mineral buildup and replacing the foam holders are considered minor problems that are cheaper and less time-consuming.
How Much Does an Aeroponics System Cost?
The cost largely depends on the type of aeroponics system to use, the species of the plants, and the number of plants to cultivate.
DIY kits sufficient for one to five plants are usually priced at less than $100. These are manual kits, nonetheless, and cannot be automated. A complete quotation by specialty stores is given only after a detailed inquiry or an ocular, more often than not.
You can buy a low-pressure pump for less than $100 and the required hoses for not over $20. It is wiser to buy a pump and a mister in package, although picking a high-pressure pump with specific features is recommended for medium to large gardens. The drainage system is heftier at $350 to $400 while a complete watering system may be bought for $300 to $400 (this includes the reservoir). Seed boxes are usually set at $1500 to $2000, but these are needed only for commercial farming and for large-scale gardening.
The price of foams, boards, and trellis are usually minimal and can even be reduced further for bulk orders.
What Equipment is Needed for Aeroponics?
Aside from common garden equipment (e.g. scissor, buckets, plastic applicators, etc.) and the essential tools mentioned above, aeroponics system may also require an E.C. meter for measuring nutrients in water-mix solution, a pH meter for measuring the acidity of the water, a thermometer or thermal scanner for temperature-sensitive crops, and measuring cylinders for manual mixing of solutions.
What Plants Can Be Grown in Aeroponics?
The best plants to grow through this method are vines, tomatoes, herbs and leafy vegetables as implied by past academic studies in aeroponics and its application to farming.
In particular, cultivating common household spices, such as rosemary, chives, sage, basil and oregano, shows good results. Different types of lettuce have also been proven by NASA to be suitable for aeroponics. Novices may start with winterboar kale, romaine lettuce, red leaf lettuce, and butterhead lettuce as they are easier to maintain.
Using aeroponics is highly recommended for those who are new to gardening and those who are living in small spaces. Learning large-scale gardening through this method might take a while, not to mention lots of resources, but it is definitely one of the best choices for urban gardening and vertical gardening.
Frequently Asked Questions
Is Aeroponics Better Than Hydroponics?
Aeroponics and hydroponics are both characterized by the absence of medium. One cannot be declared better than the other in terms of yield as it depends on the suitability of the plant to the method chosen.
Nonetheless, the former is generally accepted to be more suitable for beginners, city dwellers, busy professionals, and those who hate cleaning gardens often.
How Often Do You Water Aeroponics?
It depends on the type of plant, its maturity stage, and location.
Leafy plants may require more water or in this case, mist, at shorter intervals. Maturity also implies the need for more water, especially when it is already bearing vegetable or fruit.
Lastly, watering may be needed more often when aeroponics is applied to outdoor gardening and not indoor gardening.
Without researching the specific requirement of the plant, it is safe to implement 5-second misting every five minutes.