The headline is a bold statement. And once you read this article, you may realize that these “secrets” are in fact not so secret. Instead, the secret sauce to maximize indoor yields is comprised of the basic fundamentals. But like many things in life, true mastery of any art is nothing more than the basics mastered.
The “secret” to maximizing indoor yields is in the culmination of doing everything right. You have to check all the boxes.
What follows in this article are the actual practices that we have used to achieve two pounds per light, and at times, three pounds per light.
Our experiences “losing” in the game of cannabis cultivation
When we first began cultivating in early 2019, we were unable to achieve even one pound per light during the first several harvest cycles.
We thought we were doing everything right. We were utilizing aspects of each of the following “Secrets” I’m about to share. So why weren’t we successful?
We were not consistent in our practices. We had too many instances where this was “off” and “that” didn’t get done, so we let it slide for a week or two before correcting. We had so many instances of things not done 100% correctly to a T, that it culminated in low yields…. again and again, and again.
The biggest take away is that once you understand the “rules” of the game, you must religiously abide by them if you want to “win” at the game.
And what exactly is “winning” in this context?
Why Yield is important to Cannabis Cultivators
Growing weed indoors might be a labor of love, but let’s not kid ourselves over the fact that it is time intensive and expensive. So “winning” is
- achieving the highest yield possible, given the genetics you are working with.
- Achieving the most cost-efficient yield, on a per pound basis.
- Achieving the highest quality bud that you can, given the genetics you are working with.
Whether you are growing at home as a hobby, growing for your patients as a caregiver, or growing commercially as a way to make a living, the goal is the same: maximize indoor yields. You also want to minimize your costs and operate as efficiently as possible. And maximizing your yield does exactly that.
Think about it. You are spending money on coco, water, nutrients, and electricity in order to get your grow on. If your efforts only yield a little, does it even justify the expense? Could you go buy a few ounces at a dispensary for the same cost (and no expenditure of time)?
If you are growing as a part of a business, did you make a profit or break even? Or lose money? If you made a profit, was it significant enough to justify continuing the business? These are important considerations every grower must eventually confront.
So let us share with you our experiences and what we have learned on our road to being successful in the cultivation business.
Secret #1: Genetics are the biggest factor and have the greatest influence on yield
This is it. This is the biggest secret. There are some strains that just yield like crazy, even in suboptimal conditions, or under suboptimal practices.
When you hear crazy statistics, like this company yielded X number of pounds per light, or per square foot, or anything crazy like that, just know that genetics played a huge role.
When I see statistics thrown around by consultants about some crazy number that a guy pulled out of a room, I know that genetics were part of the equation.
If a manufacturer wants to prove the superiority of their special LED lights, or their special HVAC system, and they intend to publish their outstanding yield results in a trade magazine, like the Cannabis Business Times, I can assure you that they will be very selective about the genetics they choose to use for that study.
You can have all the best practices in the world, and the most dialed in environment, but you cannot change the genetic makeup of the plant.
So genetics are a huge component in achieving a high yield. Some strains just don’t yield well, and others produce monstrous yields. Still other strains will have mixed results, depending on a number of environmental factors.
The idea is to figure out what is an acceptable outcome for your room, grow tent, etc, and then throw in a mix of strains that will get you the average that you can live with. We all have favorite strains that yield poorly, and we keep ‘em around because we love them.
But then again, lately we are coming across more and more exotic strains that check all the boxes, including yields, which is persuasive enough to cut the under-performers. You decide what is best for your grow.
Secret #2: Trellis is an Absolute Necessity, as is using it Properly
When growing indoors, you must create a SCROG canopy, and that requires trellis. You cannot create a true canopy without trellis. You cannot get the job done with just bamboo sticks inside pots. Same goes if you have only a bed of plants with no netting.
Whether you use pots, rockwool cubes, or a garden bed of soil, you must stretch a screen of trellis over your grow space, and then put it to use.
Putting it to use means that you weave the branches through it, reaching out to squares far away. Doing so will cause many more tops to form for potential colas.
We’ve written before about how you do not want your plants to grow tall and skinny, and to avoid that, you must lay your branches down. Encourage horizontal growth. It will all grow vertically in the end anyway, that’s where the lights are. But spread that plant wide and use the trellis.
Now to effectively use the trellis, your plants must be topped during veg. So the real “secret” to effectively using trellis netting is to have plants are already topped and trained for this task.
Our Failure to Realize the Critical Importance of Trellis Netting resulted in very poor yields early on
Let me provide a humbling example of our own failures early on. As brand new cultivators, learning on the job in the early days of the Oklahoma medical market, we were driven by our passion. But we lacked the knowledge and experience.
We were aware that trellis was an incredibly helpful tool were managing the craziness of the canopy. Trellis helped control overgrowth and the weight of the branches as the plant got bigger and heavier through flower. But we were not consistent in our application of it.
We would “flip” plants from our Veg Room to our Flower rooms on a weekly basis. With our small staff at the time, moving the plants out of the veg room and into the flower room would take all day. So we would come back the next day to throw up the trellis netting. Sometimes we wouldn’t get to it until later in the week because we had other chores to attend to.
There were times when we had to throw the trellis netting up the following week. The problem there is the plants had already began to stretch, and now we were playing catch up.
We knew this was not ideal, but eventually realized how monumental the differences in outcomes were. There is a reason we are putting this “secret” as number two on the list, because it is that important to maximizing yields.
Summarizing the “secret” to using trellis to maximize indoor yields
If you are not consistent with your practice, this is our advice to get with it now. Here are some very important practices related to effective use of the trellis netting:
- You must top your plants during veg
- You should defoliate your plants in veg before flipping
- You should hang your trellis netting before flipping your light cycle
- If you are changing rooms, go into your flower room and put up your trellis before you bring in the plants
- If you are flowering in the same space, put up your netting before switching the light cycle
- You must weave the branches through the trellis during the first three weeks of the flowering cycle
In addition to this list, there are a couple other related areas, which we will get to below. They are defoliation and PPFD or light density. Both will be addressed below.
Secret #3: Maximizing your PPFD
PPFD refers to “Photosynthetic photon flux density” and is basically a scientific measure of how much light you are giving to a certain area.
You can measure the PPFD of your own garden by holding a PAR meter directly over your canopy. This tool will give you a PPFD reading.
You want to be around 1,000 or more. But you also want to have an even amount across your canopy. There will be areas with peak readings, and then there will be areas with very low readings.
Your job is to attempt to obtain an even amount of PPFD. This may require more lighting, or better spacing of your lighting.
One aspect of lighting in a large grow room is the concept of compounding “crossover” lighting. When the rays from one grow light crossover into the rays of another grow light, the result is higher PPFD.
Learning from our Mistakes, again.
Another humbling moment for us was when we realized that some of our aisles had a higher PPFD reading than the light directly over our plants. We had rows of tables. Between each row was a narrow walk space, so we could get through to tend to our plants.
Once we began to regularly inspect PPFD levels and apply a critical eye to our initial layout and design, we learned some things. We learned that the indirect light, when combined with the crossover rays of many other lights, created a higher PPFD reading than the rays directly under a single bulb. This meant that concrete floor of our middle aisles receive more photons of light than the plants up on the tables, directly under the lights.
To solve this inefficiency, we soon implemented rolling tables, that could all be pushed together. By creating one giant mass of a table, we were able to utilize every bit of compounded light. And this greatly improved our yields.
Secret #4: Defoliation
Another related factor that contributes to yield is the practice of defoliation. After the post-veg stretch, the plants are so overgrown with bush, that the sheer foliage is enough to obstruct the rays of light from reaching the most important places: the tops and colas.
A solid defoliation ritual, performed a couple times during the first half of flower, will keep your plants clean and free of debris, and ready to absorb all of the light.
We have found that failure to perform heavy defoliations, or performing only “partial” defoliations, results in much less bud yielded.
You want to yield a lot of bud, not a lot of leaf. Therefore, perform a heavy defoliation, in the vein of “lolipopping” or “schwazzing,” whatever nomenclature your prefer. Just remove everything, including bud sites, under the first layer of trellis. Above the first layer, remove all heavy fan leaves everywhere else. You will get much more bud, and much less larf.
Secret #5: You must Optimize Environmental Controls to Maximize Indoor Yields
Of all the “secrets” described thus far, this is the one that probably seems the most like a secret. But really, it’s the fundamentals prescribed above that really matter most.
Oh environment is important. But do not think that digital controls and a half a percent there, or two degrees here, is more important than genetics, topping, trellising, light density, and defoliation.
But on to the secrets…
Increasing CO2 will boost your yields, to a point
You must use CO2. You probably know this already, but achieving maximal yield requires you to check all the boxes. CO2 above 1200 is one of those boxes.
You must have the proper temperature and humidity control.
But in regards to achieving the proper temperature and humidity, what exactly is the optimal range?
Here is a real secret that is not widespread outside the commercial world: Follow the VPD chart.
At the time of this writing, this is still a rather new concept in cultivation. It’s been around, but as knowledge is still slow to increase (it’s not like Weed has been legal for that long), even commercial cultivators are still learning the ropes. And using VPD as a metric in cannabis cultivation is still not that widespread. But those that are catching on are getting insane results.
“Live by the VPD Chart, or die by the VPD Chart”
VPD refers to Vapor Pressure Deficit. It is a metric in the world of physics for measuring the relationship to water pressure in the air as it relates to temperature in the room. Without going into the science, which we aren’t even qualified to discuss (we just grow weed, jeez), here is the gist:
At any given temperature, there is an optimal humidity. So if your grow room is running at a high temperature, say 85 degrees F, then you must bring up the humidity to maintain the desired VPD. Accordingly, if your room is running colder, you would have to drop the humidity.
If equipment issues forced you to have more humidity than you want, you would increase the temperature to accommodate.
What you do is you find a VPD chart, and you attempt to stay in the range of 0.5 to 1.0. Once you review the chart, you will see what I mean.
Ivan from the Jungle Boys has stated, “We follow the VPD chart, we live by the VPD, there’s no other way.” Of all the items on this list, this is the one that currently has the allure of being a “secret.” It kind of is and kind of isn’t.
If you are keeping an eye on things, you are very likely already hitting the right VPD ranges. But once you are keenly aware of the VPD concept, you will knowingly always stick to the exact same target range. And this extreme focus, applied consistently, will definitely result in increased performance.
In sum, maximizing your yield is all about mastering the fundamentals, and doing everything correctly. It’s cumulative nature of doing all of these things:
- You have to start out with the right genetics (strains that have a potential to yield well).
- You must do all of the canopy management techniques prescribed above.
- You must have optimal light density. And if growing in a room, to optimize the weight of that room’s output, you must be utilizing all inches of the light, therefore using rolling tables. and
- you must dial in your environmental controls, and optimize using the VPD chart.
If you do all of these things, then you are doing everything you can to encourage the maximal yield that your plants can produce
And if you are not doing all of these things, now you have an explanation and a reason not to feel so bad.
You can still have a good time growing weed without CO2 or without sticking to the VPD 100% of the time, every minute, every hour.
But if you are having problems – and we consider a bad yield to be a problem – now you have some areas to review.
Until then, we are all learning on this journey. The above items are some of the biggest learning milestones that we have encountered. Discovering the above made a huge difference in our garden. And hopefully, this information will help you too.