Sonny Moerenhout with Grodan

“There is no ‘typical’ situation for the cannabis grower”

“A major challenge in the medicinal cannabis industry is the fact that because the industry is so young, sometimes the knowledge is limiting, in the sense that there are so many aspects of growing to improve,” says Sonny Moerenhout, Product Manager New Business at Grodan. Sonny is responsible for the medicinal cannabis market globally, except North America. “By doing research and sharing knowledge we’re helping growers move forward.” We've asked him to share this knowledge on growing medicinal cannabis, irrigation practices and challenges for growers.

Sonny Moerenhout with Grodan

Irrigation is key 
Irrigation is a key factor in growing. With decades of history in horticulture, the team with Grodan has built extensive knowledge in this and helps growers with precision growing. The company develops stone wool substrates for specific crops and offers solutions like GroSens, helping growers with data to take their cultivation to a higher level. Their rockwool substrate is very popular among licensed cannabis growers, and Sonny explains why he believes it to be preferable over other substrates. “For starters: rockwool does not lock up or release any substances,” he says. "But that's more a quality guarantee that we can offer, also shown by our EKO label. The biggest benefit is how the product is clean, uniform and inert, giving growers many possibilities to grow an optimum, uniform crop whilst keeping the high quality." 

The substrate is offered in blocks. Sonny, and with him Grodan, see the future of growing moving more and more toward blocks. “First of all, in medicinal cannabis you need to have a single plant system because of the plant requirements,” says Sonny. “Then also when looking at automation, plant block systems are the easiest to work with. For the future, for upscaling, and for automation, plant blocks are the way to go.”

Efficiency and upscaling
His focus on efficiency and upscaling is also why he believes in the future of cannabis in greenhouses. “There will be more pressure on the market and the prices and greenhouses will be most efficient, because light and heat are free resources inside a greenhouse and upscaling is possible. Indoor farms will offer room for specialties. And for the technical challenges: if we can grow tomatoes in the desert, why not cannabis?” 

However, there's still a lot to learn when it comes to cannabis growing. “For cherry tomatoes and vine tomatoes we have different growing strategies, but with this crop both Sativa and Indica are often grown in one greenhouse,” he says. “This will have to change, and it will change as more knowledge enters the environment." 

Lack of standards
Another challenge in the industry is the lack of standards, says Sonny. “At the moment there’s a tangle of systems in the world: indoor, semi-closed and closed greenhouses. There is no standardized way of growing medicinal cannabis yet, everyone has different opinions about it. Similarly, when looking at irrigation there are a lot of different systems in use: ebb and flow, on tables, drippers, in gutters.” 

The lack of a growing standard means that there is no easy way to advise growers, either when starting a crop or when they are in the middle of growing. “There is no ‘typical’ situation for the cannabis grower,” says Sonny. “When advising a tomato grower from Japan you can count all the circumstances and give advice quite easily, but with cannabis we have to give tailored advice based on the situation, have them fill out a questionnaire and give advice based on that, which is a lot more time consuming than the vegetable industry. The amount of hours put in per customer is much higher, and it requires a lot more knowledge.”

Rather than seeing these hurdles as obstacles, at Grodan they see them as opportunities. That's partly because of their GroSens system, which can help increase optimization in irrigation, and allows growers to be more consistent, to create more uniformity in products. “The system allows growers to keep a close eye on the hydration of their substrate, independent of their exact cultivation system, and that can be of great help to growers", Sonny agrees. "Also the current market offers an opportunity, since we can help growers based on the knowledge from our cannabis research and our knowledge in other horticultural crops. For example, the importance of initial saturation - something often forgotten when it comes to using rock wool. The blocks need to be saturated completely before being used. That's some knowledge from horticulture that helps the medicinal cannabis industry." 

Read the second article, discussing the differences between growing medical cannabis and growing vegetables, here.

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Sonny Moerenhout

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