A Guide to Growing Cannabis in Aeroponic Systems

If you’ve ever been curious to see how a cannabis plant’s root system develops underneath the green foliage above, try growing a new strain using an aeroponic environment. Growing marijuana plants in these substrate-free surroundings provide a bird’s-eye view of the intricate root system’s development throughout the plant’s life cycle.

Interestingly, aeroponic gardening originated back in the early 1920s as scientists began researching the links between root and plant growth development. Aeroponics provided an opportunity to visualize intricate rootstock outside of the soil. Their experiments revealed what is now one of the most efficient methods for growing in the cannabis industry.

Pearly white roots expose themselves quickly in these air-driven environments, promoting rapid expansion in early vegetative growth stages. Watching root systems advance in the next few weeks showcases an intricate network of hair-like appendages as bustling microbial activity advances plant growth.

By the time marijuana plants mature into the flowering state, massive root balls dangling in the air under the foliage reveal the big picture of how cannabis plant root systems develop. Aeroponic growing techniques teach cannabis cultivators how root systems progress. As an added bonus, they also produce high yields of rich trichome-dense flowers in a much shorter time.

While aeroponic environments provide a beneficial, efficient system for marijuana cultivation, there are also some drawbacks when using this growing medium. In this guide, we focus on the benefits and the disadvantages of cannabis cultivation in aeroponics systems and how to get started.

What is Aeroponic Growing?

Cannabis plants cultivated in aeroponic systems combine abundant oxygen, water, and a soluble nutrient spray, supporting the hungry environment without clinging to a substrate. They simply grow in the air. The system contains a plant bed and a misting chamber supported by an enclosed reservoir below. 

Inside the bed, protective collars cradling stalks at the plant base support the structure above. Small baskets of net pots attached to the collars underneath the plant bed allow the root system to expand prolifically.

The misting chamber contains a series of pumps, tubing, and misters, which spray a fine mist of water and nutrient solution directly at the root zone. Delivery of these atomized droplets is on a cyclic schedule. For instance, pumps spray tiny droplets for one minute, subsequently shutting off for five minutes. The down-time, when misters are off, allows the plants to absorb the soluble solution. Microbial colonization on root hairs helps the cannabis plant process the nutrient uptake. 

Excess water and nutrient reserves dripping off the rootstock are returned to the reservoir below through a drain pipe in the misting chamber. This resourceful method reduces the amount of nutrient-rich water required for optimal growth as the solution is continually recycled. 

Aeroponic growing systems are similar to hydroponic techniques as they both supply nutrient formulas directly to exposed root systems. However, aeroponic schematics take it to the next level as they deliver exact nutrient essentials without the buffer of a substrate. 

How do Hydroponic Systems Compare to Aeroponics?

Growing cannabis in hydroponic settings has long been a favourite method for growers. Deep Water Culture (DWC) designs and plants grown in clay pebbles are two examples of general hydroponic growing systems. While some submerge the root system in water, others work in conjunction with different substrates such as rock wool or coco coir to support the plant.

In all hydro systems, water is the substrate used by the root zone to grow healthy plants. The methodology provides the root system with a perfect blend of water and nutrients to encourage rapid growth. A constant supply of readily available elements allows a plant to uptake what it needs when it needs.

While the two systems are similar, cannabis plants grown aeroponically do not have substrate dependency. Instead, they take in massive quantities of oxygen to heighten root development. Without a substrate buffer, marijuana plants quickly absorb essential nutrients. This action leads to faster plant growth and ultimately higher yields.

What are the Differences Between the Two Systems?

The notable difference between the two growing styles lies within the droplet size applied to the rootstock. Large droplets in low-pressure systems (LPS) tend to fall into the hydroponic classification. Additionally, most hydro-style designs allow roots to be in contact with water.

What sets aeroponics apart is the atomized droplets emitted from the misters. High-pressure systems (HPS) showering drops less than 50 microns on the root tendrils provide quick water and soluble nutrient absorption. True Aeroponic Grow (TAG) systems deliver these tiny droplets for immediate uptake.

On the other hand, Faux Aeroponic Grow (FAG) methods incorporate top-feeding drippers into the process. Some designs eliminate the misting chamber, providing hanging roots access to the solution in the reservoir. Many DIY systems incorporate this hybrid style of aeroponic growing.

What are the Advantages of Growing Cannabis Aeroponically?

Complete Control of Inputs

Cannabis cultivators growing in aeroponic grow rooms have total control over the nutrient regime supplied to their plants. Fine-tuning the recipe for different growth stages is easily adjusted with small incremental changes. Marijuana plants flourish when grown in these systems, producing high yields with large amounts of trichome populations.

Due to the enclosed structure, aeroponic gardens require less water and nutrient solution since they are continually recycled throughout the system. Indeed, growers will save money on nutrient products as this method requires a fraction of the manufacturer’s recommended doses. Generally, only one-quarter to one-half of the suggested nutrient levels are needed in aero systems to support plant growth.

Constant Supply of Oxygen

With unlimited oxygen delivered straight to the root system, cannabis plants soak it up, helping the root system expand. Unlike soil-grown plants, often fighting for oxygen if the roots become saturated, aeroponic set-ups encourage oxygen absorption as roots hang in mid-air.

Reduces Evaporation and Pest Problems

Aeroponic structures are closed-loop systems reducing influences from outside the enclosure. The supportive collar restricts light from entering the chamber, thus decreasing the rate of evaporation.

The sealed container also eliminates many pests and pathogen infiltrations. Fungus gnats and root aphids, often a nuisance for soil-grown environments, are not problematic in these substrate-free set-ups. Mould and algae outbreaks also diminish as the sterile atmosphere restricts their ability to manifest.

More Plants in Less Space

Due to the nature of aeroponic grow systems, multiple plants can be grown in smaller areas. Perfect for Sea of Green (SOG) techniques, marijuana growers will capitalize on producing maximum yield in less grow space. Incorporating low-stress training (LST) methods and Screen of Green (SCROG) practices on cannabis plants grown aeroponically encourages plant development, resulting in a bounty of aromatic buds.

What are the Downsides of Aeroponic Growing Techniques?

Cannabis root tendrils exposed to the air are very selective about how they uptake fertilization. Dialling in nutrient recipes requires strict attention to detail due to a lack of substrate to buffer element imbalances. Exposed roots are susceptible to any outside influences, especially chemical changes.

Monitoring nutrient formulations for pH, Electrical Conductivity (EC), or Total Dissolved Salt (TDS) content measured in parts per million (ppm) is critical in aeroponic growing. If a marijuana plant is unable to uptake nutrients due to unfavourable conditions, it cannot survive.

Start with low ppm or EC measurements and gradually adjust recipes as the plant responds. Cannabis plants favour pH adjustments between 5.5 and 6.5 in aeroponics. There again, a jump from 5.5 to 6.5 when changing a reservoir can shock the plant. Slow and small incremental changes work best on sensitive air-grown roots.

Equipment Costs and Monitoring

While aeroponic systems are a simple design, cycling timers, pumps, and misting nozzle costs take a chunk out of the initial budget. High-tech aeroponic systems equipped with sensors and automation deliver a first-class experience for growing cannabis. However, they often carry a hefty price-tag.

Of course, even in an automated system, things can go haywire quickly. Aeroponics growing systems leave little room for error if the misters clog and fail to spray droplets on the roots. Cannabis plants will not survive if their root systems dry up from lack of water.

Monitoring an aeroponic system is a 24/7 commitment throughout the marijuana plant’s life cycle, whether automated or not. If the system malfunctions in the middle of the night, the root system is denied its essential life-line of water and nutrients.

Learn to Grow Marijuana Before Attempting Aeroponics

Inexperienced growers may find themselves in over their heads trying to figure out how to grow a marijuana plant successfully in an aero environment. Due to the sensitivity of exposed roots suspended in the air, the chance of mishap is relatively high.

It is best to understand nutrient dosing, grow lights, and other environmental controls before jumping into aeroponic growing. Additionally, a good knowledge of how a unique cannabis cultivar will develop through its life-cycle sheds light on what to expect in an aeroponic cannabis growing set-up.