How is growing medicinal cannabis the same as growing vegetables? Yesterday we published how their knowledge from horticulture helps Grodan to better serve licensed cannabis growers. Today Sonny Moerenhout shares more on the similarities and the differences. “I like to compare growing cannabis to propagation in tomato growing, because logistics and quality are the most important elements for running your facility optimally,” he says. “In propagation hygiene is incredibly important, just like in medicinal cannabis growing, where hygiene is also a major element."
“When it comes to irrigation we see that in cannabis, just like in greenhouse vegetables, ebb and flow irrigation works well for the propagative and vegetative phases,” he says. “When entering the flowering phase drip irrigation will stimulate Precision Growing. Drip irrigation allows you to be precise in the amount of water and fertilizer that is administered to the plant, and we really see this as having a positive effect on the flowering plant. Ebb and flow is possible, but based on tests, drip irrigation is much better for precision growing during the flowering phase.”
There's one major distinction between vegetables and medicinal cannabis, however, one that offers additional challenges to the cannabis market. "We have to be aware that cannabis is pharma, not food.”
The cannabis market requires even stricter compliances, and that offers new challenges. This goes for the laws (“First compliance, then business” is how Grodan as a company operates in new markets) but also for the grower’s rules to operate in a medical area. “For instance: is substrate considered a pharmaceutical or a regular end-of-life product?", Sonny gives as an example. "If it’s considered a pharma product that would increase the cost of recycling, which of course has an impact on our business as well.”
The strict pharma compliances also affect the cultivation of cannabis. "Many cannabis growing operations have QA managers who will define internal Standard Operating Practices, also for the cultivation process. This is to make sure their product is complying to the rules at all time. While complying is of high importance, it sometimes limits the grower’s freedom to be able to do what’s best for the plant", Sonny explains. “For example, if you have to keep the temperature between, say, 22 and 28 degrees – you can never have it go outside of those boundaries. But it could just be that the crop needs temperatures outside of those boundaries. It is still a living thing and its needs need to be taken into account. Whereas we look for standards in growing, there is no standard mode of cultivation yet."
Finding good practices
It's almost ironic, since finding good practices is currently of high importance for the cannabis growers. Sonny says it's actually the most limiting factor in the industry nowadays. “Good practices and knowledge on growing,” he says. "For example, what we see in the industry is people speaking of different strains or cultivars, but in reality we're dealing with different chemovars: the chemical compounds on cannabis, the cannabinoids, like CBD and THC, and the terpenes. That's the future for cannabis growing, and there's an ocean of knowledge to be gained. From horticulture again we know that your growing practice affects your brix level, and part our future research will be conducted to finding the same information for chemovar levels in cannabis."
Since 2016 Grodan has been one of the first companies to start researching this at Wageningen University. From that moment on they have been consistently doing tests to make sure they have enough cultivation knowledge to help growers along. "We will continue to research how irrigation affects the final product. Not just the dry material or the harvested material, but also the content: the cannabinoids and the terpenes again. There's a world out there to explore."
In addition, he points out how hybrid varieties could possibly make propagating young plants a lot easier. "The importance of the quality of the starting material and the maintenance of the mother plants is often underestimated nowadays,” he says. “The quality of the cuttings is important in order to make good pace afterwards. However, hybrid varieties would be a game changer in this industry."
“Until that time we have to work with what we have, and on top of that the reality is that it’s hard to find people that have good knowledge about growing this crop,” says Sonny. “Most knowledge comes from the illicit market, but this is often growing with much smaller numbers.”
In order to make the most of this knowledge, these veterans of the industry need to work with veterans of the horticultural industry and combine their knowledge, he believes. “We need these growers to learn more about the plant, and they need us for the large scale plant knowledge, to explore the relationship between climate and plant. Maybe they can tell that a plant is not healthy, but figuring out why can be quite difficult without prior knowledge of large scale horticultural practices and plant physiology."
As an example, he shares that flushing, a common occurrence in the final stage of the cannabis crop, might not be of use at all. "I'm not saying it is, but so far the research that we're doing points in that direction. There are other habits from the underground scene that will turn into common growing knowledge though. Finding this balance, finding the reality is why working together and sharing information is of high importance. Combining plant knowledge with the systematic thinking of horticulture can help the whole industry further."