We heard loud and clear from our May and June 2020 CANNAtalk Experience virtual event just how massively important canopy management is to maximizing your cannabis crop. Master Growers have vital questions, opinions, and insights about choosing their plant density, defoliation, netting, and more.
And to expand upon discussion at our Virtual Event, in August 2020 expert members of our CANNAtalk Passionate Growers LinkedIn Group answered multiple polls and provided further insightful comments about their own canopy management best practices.
So, in this extensive article we share the best canopy management ideas (and frustrations) from your fellow Master Growers from our Virtual Event and our LinkedIn Group. Here we go!
1. What do you focus on most in your canopy to maximize your crop, and why?
Master Grower William Fournier, CANNA product development advisor, LP consultant, and “budding” LP facility owner, polled members of the CANNAtalk Passionate Growers LinkedIn Group about what canopy management activity they focus on most. However, there was no clear winning method:
With 44% of the vote, “Shape and size of the plants” edged out “air flow” that had 33% of the vote. In the comments that followed, master growers advocated for their favorite methods that did not win the poll:
- AIRFLOW: Meurig M., Flower Supervisor at Zenabis Global Inc., wrote: “If I had to pick one, it would be for airflow. It's great for mitigating micro climates and evening out the temperature/CO2/humidity for more accurate readings and prescriptions. The more you invest into your HVAC and air circulation system, the less you need to remove.” (Meurig has more to say about airflow in just a bit.)
- WEIGHT SUPPORT OF THE FLOWER: Will Fournier wrote: “In case of lack of time or resources, I always prioritize the netting for plant support. I had chaotic results when skipping this step once, never again.”
- Also, a new top answer emerged: ALL OF THE ABOVE, which was the most liked comment! As Alexandre Gauthier, Master Grower at Origine Nature wrote, “I can’t vote, all 4 are equally important. You overlook one and the rest goes with it.” That idea was seconded by Alexander Weiland Roy, Production Manager at Organigram Ltd: “All four are equally important. All will play a factor in plant health, development, and shape and each environment requires a niche combination of all four!!” Finally, Mikael Rykes, Cultivation Operations Director at GOOD BUDS also agreed with “all of the above,” but wanting to add “plant density” to the four choices. BUDS also agreed with “all of the above,” but wanting to add “plant density” to the four choices.
While those were the concise answers on our LinkedIn Group discussion, this same question provoked some of the most interesting and heartfelt debate within the Canopy Hub of our Virtual Event. Listen in to these passionate Master Growers:
- Meurig M., Flower Supervisor at Zenabis Global Inc: “I find that in most cases there are huge fans on the edge of the crop space and the plants are only two feet away from them, which can just wind whip them, forcing transpiration and just beating the canopy causing the plant to focus on stability rather than reproductive production. But you still have to get the airflow to the plants that are in the middle of the room or where your microclimates are the most dense. I do a lot of finesse/purpose pruning, so I can have fans on minimal settings, that will still move air as far as possible but also as gentle as possible. I match the amount of pruning cycles, styles, and techniques to the purpose of the plant and my growing environment. Sometimes I may have to prune a plant using a less ideal combination to match the environments or else you're not really maximizing your potential income. And at the end of the day, that's really the whole point of the business facilities.”
- Bobby Bains, Head of Cultivation, Delta 9 Cannabis: “This is a good debate that we have on the production floor between different section growers. Some like going really hard on the defoliation and some that say, you can't defoliate, those leaves matter. And some people say, well, I want air through my canopy and there’s people who say, well, what's the point of having air if your plants can't take up all that light. So, yeah, no, this is a tough one. I guess it all depends on your grow room, your approach to cultivation, the way your grow rooms are designed, the size of your plants.
2. What is the most harmful canopy management method?
Unlike the first question, the answers were unanimous: Master Growers chose extreme defoliation as the most harmful canopy management method:
Survey takers backed up their unanimous disapproval of extreme defoliation with comments sharing the poor outcome of their previous experiences:
- “Extreme defoliating and extreme lollipop when not done correctly can definitely hurt yields. Also, both can be very dependent on the cultivar and how it branches, etc.” Damages included “overall slowing of bud development/end yield. The technique can yield great results when done properly but if not timed right or the nutrient regime is incorrect it can be detrimental in some instances.” – Mikael Rykes, Cultivation Operations Director, GOOD BUDS
- “I also experienced nutrient lockup once (with extreme defoliation). I even saw some plants so stressed they made male pre-flower... definitely a risky method when not done properly!” – William Fournier, CANNA product development advisor, LP consultant
- “Lollipop and extreme defoliation med-men style really doesn’t work with all genetics. Most people defoliate too much, too soon.” – Alexandre Gauthier, Master Grower, Origine Nature
- “Alex is bang on for me it’s extreme defoliation, and really anytime it’s not done right. It takes skill to know how to and how deep to go. You can cause a lot of damage to yield.” – Christopher Lentile, Operations Manager, Port Perry Campus at Aleafia Health
Doug Jacobs, Technical Advisor at The GRODAN Group, shared what another canopy management method – topping -- he thought was too harmful:
- “Topping early and often slows plant development and can lead to different crop structures that would create uptake issues in the rootzone.”
3. What shape do you aim for prior to flipping your plants, and why?
William Fournier asked the CANNA Passionate Growers LinkedIn Group about their desired plant shape for the key pivotal moment before flipping their plants from the vegetative stage to the flowering stage.
To get the party started, Will shared a photo of his ideal plant shape, and wrote: “I understand that plant shape depends on many factors like plant density and strain type. I usually go with 9 plants per 20 square feet and when the genetic allow me to cut the main apex, I aim for a shape like this:
Several members of the CANNAtalk Passionate Growers LinkedIn Group responded with mostly approval:
- “That’s perfect!” – Damian Soloman, Plant Geek Consulting LLC / Harvest Health Chief Botanist
- “I usually go for something similar myself but usually have a higher plant density and slightly less topping to shorten veg times. Looks good.” – Mikael Rykes, Cultivation Operations Director, GOOD BUDS
- “Plant structure is very important to standardizing your product and streamlining the process of taking care of the ladies. Pinching the main apex is always a good way to promote a good structure. As far as plant density it’s all about the strain and the stretching, but 9 plants per 20 square feet is a good starting point.” – Alexandre Gauthier, Master Grower at Origine Nature
Not all commenters were in full agreement with Will’s desired plant shape. Jose Dominguez, Cannabis Sommelier & Formulation Specialist, Neptune Solutions Bien-Être, had a different perspective:
- “Lots of wasted (nutrients), energy, work, time and money with that structure. Why remove all the bottoms and not start flowering earlier? Vegetation stage takes a few weeks to grow a 1-foot plant and then everything is removed and kept again for longer vegetation. Seems like a waste to me. Also, how would you feel to get a 10-foot straw in your drink? That’s how those plants feel in my opinion.”
In reply, Will Fournier went deeper in the benefits of his ideal, before-flipping plant shape:
- “I hear your point! I found that it’s more efficient to deleaf and get the structure the right way before the stretch starts. It minimizes the amount of workload after the first few weeks of bloom. Not to mention that it becomes easier to standardize your canopy in the top tier so less variation with the potency. Your input is great, I agree that you need to capitalize on the stretch period. Cheers mate!
4. Are grow rooms space efficient and well-utilized?
According to the Master Growers at our Virtual Event, sometimes grow rooms are space efficient and thus well-utilized, but unfortunately too often they are not.
Factors that help space efficiency and utilization:
- You maximize your canopy.
- You have to have enough space to walk around and do the work you need to do.
- You have enough space for storage.
- You can manage the climate of your space, including humidity, airflow and temperature.
“Space efficiency is not just maximizing the canopy -- it's also about maximizing the efficiency of the employees. You have to be able to work, and perform needed tasks according to the cultivation plan. If you grow larger plants, you probably will require more access space around the plants, compared to sea of green where you utilize common walkways with a higher plant density.” – Nico Hache, Director, CCI Deloitte
Factors that reduce space efficiency and utilization:
- Wasted space from too many walkways in the grower rooms where there are no plants there.
- The tables are so wide apart, because you are not using rolling benches
- You have a giant room and for whatever reason you limited your lights but then only put tables where the lights were hung.
- Your canopy space needs are frozen by your initial business plan.
“In the early days it was all about the square foot of canopy you could throw into a business plan, but then you get committed to that plan and it’s tough to make changes and pivot.” – Patrick Scanlon, Head of Cultivation, CannTx Life Sciences Inc.
5. How do you manage your canopy when it contains more than one cannabis strain within the same environment?
In this final, passionate discussion about canopy management from our Virtual Event, Master Growers struggled with the too-often misunderstood need to provide different, tailored environments to multiple strains, with the business reality of one large room to grow them all. Especially with orders handed down from distant, uninformed management. This same struggle extends beyond canopy management to include fertigation and root zone management.
- Meurig M., Flower Supervisor at Zenabis Global Inc: ”...if you have a genetic strain that originates at the foothills of the Himalayas, and then you have another genetic strain that comes from the jungles of Thailand, they're not going to have the same environmental requirements. For the best success you can have with a particular cultivar, you must create a cultivation strategy around it. Not try to force success by making the plant fit the cultivation strategy."
- Nico Hache, Director, CCI Deloitte: “ We struggled growing Acapulco Gold because of our standardized approach trying to grow all our cultivars in the same manner and environment. This particular cultivar required a very different flowering process compared to our other cultivars. It would keep well as a mother plant and clone production was similar to our other cultivars, but during the flowering stage, at roughly 6-7 weeks, the plants showed signs of senescing and the flowers would abort. This made us look at grouping similar plants together and customizing cultivation plans for specific cultivars. This increased our overall quality and production capacity on all our cultivars and more importantly, we were able to harvest a successful crop of Acapulco Gold. It is important to clearly communicate this to the production planning team to assure this is taken in consideration when doing crop planning activities. ”
- Patrick Scanlon, Head of Cultivation, CannTx Life Sciences Inc.: “We came to a compromise. I was willing to run one germplasm per irrigation supply line. So as long as I had some ability to prevent using some kind of average nutritional recipe, then that was a reasonable compromise. But it is a challenge, especially in the mother room, as good vegetative growth requires different environments per germplasm, because of the lineage, growth characteristics etc. So, it's definitely a challenge.”
Now you know what Canadian Master Growers feel works best for managing their cannabis canopy, from plant shape, airflow, defoliation, to setting up the grow room, and negotiating with their management. We are grateful for the open and honest discussion these cannabis pioneers shared with us, so that we can share it with you.
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