As some of you are aware, I've been pushing the concept of flowering in cool/dry conditions for many years now. I vastly prefer the quality it produces, and am unable to easily find it anywhere else. There are other variables involved than simply dropping RH, and I've tried to include as many as I could think of in this post.
SO... I give you a bit of context of where I'm coming from, a description of my preferred end product, and provide my best explanations on my how and why of it.
Cannabis is My Medicine
I use cannabis all day, every day, for a variety of medical reasons. I'm autistic, very intelligent, have adhd, dwindling anxieties, birth defects and injuries which have created lifelong character building. I'm working on taking consistent and detailed notes, and unfortunately this is a recent pursuit. I've never grown for the purpose of selling, and all of my cannabis goes to myself, my wife and occasionally shared with a few friends. I've not weighed a harvest in over 10 years so i really haven't any data on 'weight.' I do know my cannabis, gram for gram, generally lasts 2-3 times longer than what I get from other growers. Even when we're growing the same clone, there's a significant difference in the structure, frangibility, terpene profile and cannabinoid content, vs. 'the norm.'
The Accidental Path
The simple truth is, I doubt I ever would have figured this out if I'd started growing with a budget. I've lived in ridiculously dry conditions for nearly all of the 15+ years I've grown cannabis. Without a budget, the least expensive environmental variable I could control was temperature. With conditions so dry, only cooler temperatures gave me adequate plant health.
The End Result I Work Toward is Head Stash Quality Cannabis
Smoking your cannabis should be almost the same experience as whole flower vaping it. Unless the strain is a particularly unpleasant flavor/aroma combination, the experience should be like inhaling a rich dessert. Soft and cool air, densely packed with flavor and aroma. Even the exhale tastes and smells awesome enough to eat.
I've found myself chomping at the exhale so many times it's ridiculous, not to mention delicous. As you toke a tightly packed bowl you can taste the 'burnt plant' flavor of the flower itself, mixed in among the flavors and aromas of the terpenes and cannabinoids. As the bowl slowly turns to a light and fluffy ash, you notice the 'burnt plant' flavor increases only ever so slightly, leaving the last hit in the bowl a tasty one. Even the exhale of the last hit in the bowl is tasty. A truly remarkable experience.
The physical structure of the flower has a different ratio of stem to flower content. You literally have a single stem in each flower, which significantly reduces searching for stem bits and the number of joints with stem holes poked in the paper. The frangibility of the flower allows it to break into tiny, frosty pieces with gentle pressure from your thumb and fingers. The biggest issue with rolling joints is how sticky the cured flowers are. With an already frosty strain, joints will literally drip resin before you're halfway through smoking it.
The Number One Key to Quality Cannabis
(in my opinion)
is understanding phytoremediation, and how this drastically effects nutrient uptake and end quality in cannabis
. Simply put, anything in excess which cannabis can absorb, will gladly be absorbed by a cannabis plant. Should this excess remain in the plant for too long (I have no input on what is too long for what or when, these are questions I would like the answers to), cannabis will paint/bind those atoms/molecules on new tissue growth where it will never flush out. The best nutrient 'mistakes' you can make with cannabis are underfeeding it.
My method includes:
Extra Veg Time
High Air Exchange Rate
Low Incoming Air Temp
Low Incoming RH
Higher Transpiration Rate
Lower Nutrient/Amendment strength
Full and Cyclical pH Swing in the Root Zone
No CO2 added
Lowered nutrient demands late flower
How Much Extra Veg?
You'll have to veg a lot longer for the same weight as hot/wet grows. Taken with a 50lb bag of salt, I'm thinking a rough guesstimate would be 1/3rd larger plants before flip. Veg at higher temps/RH, as long as flowers are not forming your quality will not be diminished. I've historically used bloom nutes for veg, simply because it's what I had originally for years. I have to say I like the shorter, stockier plants for canopy management, and also for supporting the heavier flowers.
Air Exchange Rate
3 complete air exchanges per minute, with as little 'direct airflow on the plants' as possible. I generally have the air hitting some other surface first before coming in contact with the plants.
Incoming air Temperature
68F/20C and HEPA filtered. I attempt to create a vortex of air along the walls. The indirect air comes in below the plants, moving up through the canopy.
Canopy Temp Max 70F/21.1C
I have a theory I'd like to test. Keeping canopy temps at 70F and below retains the more fragile monoterpenes. I believe these terpenes may be contributing to the polymerization of the more complex terpenes. I know many times I can lick my lips 30-45 minutes after smoking a joint, and still taste the awesome terpenes remaining there.
Incoming RH has always varied. As low as 15%, and as high as 25% Without a budget, my attempts at raising RH were unfruitful, so I gave up. RH above the canopy is higher, as I normally run hydro. In the desert I ran a/c, at 10k feet in the rockies I mainly used cold/dry mountain air.
High Transpiration Means Same Nutes, Diluted with More Water
The lower the RH, the lower your temp and nutrient strength needs to be. Your plants will be using significant amounts of water to stay hydrated, and this means pulling a lot of nutes with it. Many of you have experienced heat spikes, where excess transpiration brought excess nutrients/amendments with it. This situation is similar, except the transpiration rate is from the plant attempting to stay hydrated.
Ambient, and as far as I'm aware it's almost always been below 800ppm. I have only played with boosting CO2 a few times and it was years ago. I did not see any point in continuing.
I run hydro and prefer DWC, so nutrient temps are always between 65F/18.33c and 69F/20.55C. I know soil and drip through media do better at higher temps, which is another reason I prefer DWC. I'm really unsure how to do what I do with soil and a healthy/warm microheard.
Root Zone pH Swing
I'm unable to stress the importance of a full and healthy pH swing in the root zone. The cyclic movement through all healthy pH ranges allow the plants to easily absorb elements they need, lowering the overall strength required for full and healthy growth.
At flip there is no explosion of growth, no insane stretch and I've never seen an NLD-dominate hybrid triple in size. The plants will speed up in growth for sure, just not nearly as much as you're likely used to.. At peak of physical flower bulking, I can go through up to 5 gallons of water a day for a 1K HPS DWC setup. Once physical flower bulking quits, transpiration will drop off unless your nutrient/amendment strength is reduced. I can see using lightly amended soils, with teas the last few weeks for greater control. Some strains drop the pH quite dramatically, and I'm looking for more info on which elements the plants are looking for most. Historically I've used potassium carbonate powder as my pH up and GH nutes with the basic Lucas ratio.
This photo is the best example I have of premium results from this process. It's from a clone of "Pink" (pre-2.0) from Avi a few years ago. Anyone who knows "Pink," will see the trichome density difference right away.
Challenges moving forward:
- Identifying a quality 'balanced' feed for CMH'ish spectrum LED lighting
- Working with the lack of IR from HID lamps
- Testing various UV and far-red levels and schedules while maintaining original quality
Thoughts, questions, expletives? I want to learn more about the why, while improving the process and quality. Thank you for your time and thoughts.