It is theorized that the cannabis plant was domesticated by our ancestors thousands of years ago. From its origins in Central Asia and possibly including the Himalaya foothills, people have long been fascinated by this plant and the uses we could derive from it (Piomelli & Russo, 2016). Cannabis researchers postulate that the first growers of cannabis crops utilized the fibrous stalks and the nutritious seeds and found the psychoactive effects after (Lawler, 2019).
There are many ways to cultivate this plant; it can be grown inside and outside, and those environments can vary in cultivation methods. The plant wants to grow well, so with a little knowledge and providing for its basic needs, it will thrive. There is definitely room for error as cannabis can be sensitive to environmental changes such as light exposure, extreme temperatures, nutrient deficiencies/excesses, and of course pests and diseases can run rampant. Although this plant can grow prolifically on its own, it needs a bit of help when it’s grown for certain crops, like the flower market. In the case of floral hemp, it is important to cater to the garden’s needs so as to encourage more flowers and trichomes. Staying observant and attentive will only yield happy, healthy, and abundant plants.
Unlike high THC cannabis, hemp is primarily grown outdoors. It can still be grown indoors, but this is not often the case. This is due to hemp’s legal status, which states that hemp can be grown everywhere in the United States as long as it complies with a given state’s regulations, since states still have discretion when it comes to hemp cultivation laws. Besides the growing medium and location (inside or outside), nothing else varies in the plant’s needs. It will need a light source for a certain amount of time during each cycle (vegetative and flowering), proper nutrient levels, appropriate amounts of water, and when necessary, it requires disease and pest management. The focus of this blog is to discuss the different cultivation methods and growing mediums for the floral hemp market.
Indoor vs Outdoor
Growing methods can be determined by a few factors, such as overall budget, growing knowledge, and cultivation space. The goal for a floral crop is to produce an abundant amount of flowers laden with trichomes which takes a certain level of skill. Compared to the other hemp crops (fiber and seed), they require less cultivator involvement and skill. Hemp can be successfully grown inside through a variety of ways, but there are less options with the outdoor method. For indoor growing, this is due to the fact that we are creating the whole environment to grow these plants, therefore growers can be creative with their growing methods.
Many people prefer to start their hemp plants inside and transition them outside in a field to finish out their life cycle, but growers can still manage a crop in an indoor facility. The reason growers like to start their hemp inside is to ensure a successful germination rate as well as to minimize plant loss; if they were to be directly sown in the field, the plants would be overrun by competing vegetation and insects. The size of the crop will also configure the ideal location because it predetermines if an indoor facility would be a feasible option; this is because the size of the grow room will dictate the amount of plants. Seeds or clones only require a small space to start out, but they will eventually need to be moved to their final grow space. If not transplanted at a certain point, the young crop will get stressed out and risk casualties.
For indoor grow operations, there is a choice between a number of options because the growing elements are being created and controlled. Cultivators can employ container gardening that can be broken into separate categories such as soil or soilless mediums (hydroponics and aeroponics). Indoor methods range from the most simple to the most complex growing systems. For outdoor growing, there is the option of putting plants directly in the ground or in containers. There are benefits and disadvantages to all methods. A person’s budget and growing experience will help to determine the cultivation process.
Hemp wants to be grown in soil with a lot of sun. This is the original method of growing for all crops. Until humans became more sophisticated concerning their cultivation methods, planting crops in the soil was the only way. Now, there are many ways to grow plants! In order to grow hemp well in soil, there are some aspects to keep in mind.
The soil needs to be at a certain pH, in the range of 6-7 on the pH scale. It will grow in ranges above or below those levels, but it won’t produce high-quality flowers. The soil cannot be compacted because plant roots need aeration. This keeps the soil from becoming anaerobic because when too much water is introduced, roots can get waterlogged and essentially suffocate. Recall that this plant does not like “wet feet.”
The soil also needs to contain organic matter because this provides all the nutrients for the plant. Most often the indoor growers are not using mineralized soil in container gardening because of “issues of drainage, contamination, and variability” (Williams, 2019). The potential of contamination consists of herbicides, pesticides, or heavy metals. Instead of collecting soil from an outside location, growers are more likely to incorporate either peat moss, coconut coir, or perlite into blends with, or without compost. Many growers are (and should be) using organic soil and soil amendments such as compost and supplemental nutrients. These can be used to amend the soil before planting the crop to rejuvenate the native soil or when filling containers. Part of the reason growers are using containers outside is due to poor quality soil. This could be the result of nutrient-poor soil, hard-panned soil, contaminated soil, or the soil is not the preferred type for hemp growing.
Utilizing soil as a medium can be very forgiving to growers for a couple of reasons. If one has over or under-watered their plants or given too much or too little nutrients, the plants will be fairly resilient to an extent. That is to say, the shock from those scenarios wouldn’t be as upsetting compared to the hydroponic or aeroponically grown plants. Growers should always make sure their plants are well taken care of in order to avoid these disturbances.
However, it is important to keep in mind that soil media does have its drawbacks. Some issues include potential pest infestation, contamination, nutrient deficiency, and also it grows slower than the hydroponic or aeroponic systems. It can get costly as well if one has to amend a large amount of soil with organic amendments, or fill many containers with different substrates. Prices of soil and other amendments can vary depending on your region. In the end, using soil or different substrates can be a great way to start out and even sustain a long term growing operation; it’s just a matter of preference.
Hydroponics / Aeroponics
This method is a very common form of cultivation. It’s important to note that it’s not exclusively for cannabis crops, although high THC and high CBD cannabis varieties do very well in a hydroponic system. This cultivation method essentially grows plants in water without the need of soil. Plants are submerged in a substrate like rockwool and receive all of their nutrients via the water. This system still requires the necessary equipment as the soil method, such as the lights and nutrients, but it needs more of a setup and a rigorously controlled environment. This method is very popular amongst seasoned growers and is quickly becoming a viable option for first-time growers.
Many people want to grow hydroponically for a number of reasons. They utilize water and nutrients efficiently, produce large yields, mature quickly, and save space. The risk of pest and disease infestation reduces greatly because most pests and diseases are soilborne. Hydroponic systems can be implemented in a greenhouse and potentially outside if a reliable power supply exists closeby. It can be a bit more challenging for a first-time hemp grower to start off with the route of hydroponics because it requires a bit more skill and knowledge, but it’s not impossible. More companies these days are offering pre-made nutrient solutions and setups to help offset these challenges of having to mix nutrients or build a system from scratch. When done correctly, water and nutrients won’t be wasted because the plant’s roots will receive the proper amounts. One can potentially examine the roots to ensure they are healthy. This method offers a lot of control which can be the technique that some growers are looking for.
A basic setup requires many supplies. These include lights, nutrient solutions, a tank for water and mixing nutrient solutions, growing containers, a substrate like rockwool or clay pellets, a pump for irrigation, and electricity. The more complex it gets, the more supplies will be needed to accommodate the increased complexities. Growers can choose between a couple of different options of hydroponic systems like deep water culture, nutrient film technique, and more. As cultivation of floral hemp ramps up, cultivators of any scale would benefit from this growing method.
There is room for plenty of error despite all the benefits that hydroponic growing offers. Due to it being tightly controlled, a lot can go wrong. Too many nutrients can burn the roots and have dire results. Incorrect pH levels and improper water temperatures can also be very damaging to the plants. It’s extremely important to have a reliable source of electricity and a strong pump (depending on the scale of the operation) in order to maintain the system. A lot can go wrong, but when it goes according to plan the results speak for themselves with the harvest.
Aeroponics is a relatively new development in the agriculture world. This new form of growing accommodates both varieties of cannabis. It can really benefit large scale operations because everything is automated and controlled. This process is very similar to the hydroponic system, but with an alteration or two. Aeroponic systems simply mist water onto the roots which are suspended in mid-air and recirculate the water. It will require all of the supplies necessary in a hydro system which are lights, nutrients, grow trays, and a water tank.
The benefits to this method include less waste of nutrients and water. It requires about 20-40% less water compared to its hydroponic counterpart. Due to the roots being suspended in the air allows for maximum oxygenation and allows a grower to examine the roots to ensure they are healthy. Another benefit to this technique is being able to harvest these plants quickly and efficiently, while not compromising on flower quality or trichome abundance. Similar to the hydroponic method, aeroponics does not have the risk of pest and disease infestation the way soil media possesses. Although this method requires less water, the energy needed to run this system can be a drawback. It is important to ensure the power source is functioning optimally because aeroponics, like hydroponic growing, requires 24/7 power. Another disadvantage is the price of setting up this system and the cost of establishing it, not to mention powering it. This is still relatively new, so the cost of production has a bit of an upfront cost. Though with harvest times rapidly sped up, the startup cost should be covered relatively quickly. The learning curve here should be taken into account as well.
A Grower’s Choice
As the hemp industry is constantly evolving, it is safe to assume that growing techniques will also change. Cultivators will want to switch up growing methods, so as to find the method that works well for their experience, region, and plant genetics. There isn’t a one size fits all approach because there is so much variety to explore in terms of the genetics and cultivation techniques, not to mention the size of scale of the growing operation. It is recommended to try out a few different approaches to see what works well. These are living beings and they want to thrive just as much as you want them to. Be good to the plants and they will be good to you.
Hemp in a field- Jillian Thayer, 2019
Aeroponic Systems. (n.d.). Retrieved from https://hydrobuilder.com/hydroponics/complete-hydroponic-grow-systems/aeroponics.html
Clarke, R., & Merlin, M. (2013). Ethnobotanical Origins, Early Cultivation, and Evolution through Human Selection. In Cannabis evolution and ethnobotany (1st ed., pp. 29-58). Berkeley: University of California Press.
Guidelines for Cannabis and Hemp cultivation in hydroponics facilities. (n.d.). Retrieved from https://cannabisgxp.com/2019/04/29/guidelines-for-cannabis-and-hemp-cultivation-in-hydroponic-facilities-2/
Klibaner, B. (2019, July 30). Why Growing With Hydroponics Is Better Than Soil. Retrieved from https://www.leafly.com/news/growing/opinion-why-growing-hydroponics-is-better-than-soil
Lawler, A. (2019). Oldest evidence of marijuana use discovered in 2500-year-old cemetery in peaks of western China. https://www.sciencemag.org/news/2019/06/oldest-evidence-marijuana-use-discovered-2500-year-old-cemetery-peaks-western-china
Piomelli, D., & Russo, E. B. (2016). The Cannabis sativa Versus Cannabis indica Debate: An Interview with Ethan Russo, MD. Cannabis and cannabinoid research, 1(1), 44–46. https://doi.org/10.1089/can.2015.29003.ebr
Williams, P. (2019, December 19). 3 tips for selecting growing media for cannabis. Retrieved from https://www.greenhousemag.com/article/production-3-tips-for-selecting-growing-media-for-cannabis/
Youngblood, T. (2020, March 20). Aeroponics 101. Retrieved from https://www.cannabistech.com/articles/aeroponics-101/