Canopy ratio is a cannabis cultivation term that I have been using for five years or so and I’ve not seen many other cannabis professionals use it or another term that means the same thing.

So what is it and how do we measure it?

To use some round numbers to illustrate, let’s assume we have a flower room that is 25’ long by 40’ wide, for a total of 1,000 square feet. In that given space, let’s say we have 750 square feet of flowering canopy. Our canopy ratio would then be 75%. So why focus on this number? 

To me, the canopy ratio is a metric to determine how efficiently a facility is using their floor space. The higher the canopy ratio, the more effectively the operation is using its real estate. It is possible to have canopy ratios higher than 100%. How? By going vertical. If you are growing in multi-tiered racks, it is likely that you can get a canopy ratio higher than 100%, especially if you are growing in three or more tiers. 

That said, growing in a multi-tiered racking system may not be the best model for everyone, although that is the trend I’ve been seeing in newer cannabis cultivation operations for the last several years. Why? 

There are many concerns surrounding multi-tiered growing, which I’ll cover in a future post. To quickly name a few, productivity / yield on racks that require a ladder or lift is rarely as high as the tiers that enable growers to access the plants without using additional equipment; safety is a major concern as well. There are other capital expenses to factor in, but that’s beyond the scope of this post. 

Now that we understand what canopy ratio is, what is a “good” canopy ratio? 

As with most things in cannabis cultivation, the answer is “it depends”. It depends on whether you’re growing single tier or multi-tiered. For single-tiered systems, the best canopy ratio I’ve seen is around 85%, with the additional 15% of space required for aisles for employees to move within as well as space for ventilation or other equipment to support the canopy. 

For multi-tiered systems, there’s a sweet spot. On the right sized rooms, I’ve seen canopy ratios ranging from 102% to 110%. If your room is too large, then the ventilation requirements consume a considerable amount of space in the room and your canopy ratio suffers. If the room is too small, mobility becomes a real challenge. Ratios higher than 110% raise alarms to me that the environment may not be controlled as tightly as it needs to be for a maximally effective crop. 

Let’s look at a few examples:

For ideal rooms with excellent controls with ratios of say 105%, you may average 75 grams/SF across your tiered canopy and be able to pass testing on the majority of the flower, say 90-95%, resulting in 68-72 grams/SF of usable cannabis that may hit the shelf as flower. 

So if your room is that same 1,000 SF as in the example above, that’s 1,050 SF of canopy, producing 75 grams/SF, passing around 70 grams/SF. This could yield a harvest of around 162 pounds of flower to be trimmed, packaged, and sent to a dispensary for retail sale.  

Conversely, let’s look at that same 1,000 SF room pushing the limits of a 120% canopy ratio and suffering from the expected lack of environmental controls such as temperature and humidity control. We’ll assume the same yield, though most would argue that the yield would be slightly lower due to mobility constraints for employees. However, let’s assume the same 75 grams/SF to isolate just the control impact. Since our temperature and humidity have fluctuated considerably throughout the lifecycle of this harvest, we only pass 80% of the flower for an average of 60 grams/SF of sellable shelf flower. The rest has failed due to mold deep inside the flower because of ineffective airflow and humidity control. Even though our canopy is larger, at 1,200 SF, we’d only yield around 158 pounds of flower to be trimmed, packaged, and sent to a dispensary for retail sale. We’ve yielded 4 pounds fewer, in a larger space that required more costs with inputs such as electricity, nutrients, pest management, and most importantly, labor. 

If you have a canopy ratio lower than 80%, you have an inefficiency present that may be able to be improved. Not all inefficiencies can be rectified, such as the presence of support columns, but evaluating it is a valuable exercise to be able to increase your canopy ratio in all of your rooms – whether it be the propagation room, mother room, veg room, or flower room, since this will transfer directly to your bottom line.