Flowering Cool and Dry for Premium Smoking Quality Cannabis

[Douglas.Curtis]

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.

Relative Humidity
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.

CO2
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.

Root Temperatures
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.

Summary
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.

 

[Cvh]

Yet again another great thread! Thanks for bringing it to the masses.

I would also really like to see you do one day a side by side with UV supplement.
The so called benefits of UV supplementation is been bugging me for years.

 

[Douglas.Curtis]

Yet again another great thread! Thanks for bringing it to the masses.

I would also really like to see you do one day a side by side with UV supplement.
The so called benefits of UV supplementation is been bugging me for years.

Thank you. I know it will become the norm in the future, and I'm greatly interested in any insights from this.

You'll be happy to know, I specifically ordered my OrigLite LED without far-red, and without any UV. I'll be picking up some UV and far-red led kits, and I'll be able to use them in one corner. Running all the same clones will show individual differences from the additional spectrums.

 

[siftedunity]

so are you saying that all the other growers who are selling very high quality bud- eg, 80f+, correct vpd, and co2 are not as high quality as your own?

 

[Mars Hydro Led]

wow, this is really an informative thread. Douglas. Thanks for sharing your grow experience with us.

 

[Douglas.Curtis]

wow, this is really an informative thread. Douglas. Thanks for sharing your grow experience with us.

My pleasure. Appreciate you stopping by.

so are you saying that all the other growers who are selling very high quality bud- eg, 80f+, correct vpd, and co2 are not as high quality as your own?

Exactly correct, yes. Everything is relative to your own experiences, and what others are calling top shelf is (in my experience) only 'decent' quality cannabis. Stretched flowers, excess stems, puffy/thick leaves, low terpene and resin content (in comparison), and often very tough to break up.

After 15+ years of growing, and 10 of those spent chasing quality, I find myself living in the middle of a desert. Occasionally there are small oasis of passable quality water, mostly not. What we need are lakes of high quality water(cannabis). This needs to change soon, and you'll all be thankful when it does.

 

[TheForgotten]

Hi there DC
I hope you don't mind me chiming in after i ran my mouth in that other thread....


The technique i will describe leaves buds that are soft to the touch, smoke cool, leave a very grey ash, and will burn on and on (joint) even when sitting in an ashtray.

I grow my plants with organics from cutting until about a foot tall,
this beginning helps the plant to have a strong immune system, and be lush and soft (no chem. salts),

then they get a few weeks of mild chemical fertilizer while continuing the organic feed (2-3 weeks),
this forces growth and the chemicals also force some organic amendments into the plant,

then they are triggered on organics until three weeks flowering are complete,
this allows a buildup of organics within the plant while not stressing them during transition to flower,

then they get a mild chemical fertilizer again for a few weeks while continuing the organic feed (2-3 weeks),
this forces size and weight into the flowers,

then they get organics until there is 2-3 weeks left,
this again allows a buildup of organics in the plant,

at which point they get a proper flush (5 gallons water per gallon of soil) and then water only until the leaves are yellowing right up to the buds.

I defoliate immediately before i harvest, removing only the leaves with petioles and cut the plants whole just above the soil line, this allows for the plant to move sugars and chlorophyll in the plant while they dry, and hang them on coat hangers in a room that never gets above 70 degrees (a hot dry makes for a hot smoke).
Then they hang until dry on the outside and get put into contractor bags (still on coat hangers) overnight,
the next day they are removed and again dried until dry on the outside, and put back in bags overnight,
repeat until buds seem as dry in the morning as when they were bagged the night before, this process is almost always 15 days, and the plants don't just dry, they also cure somewhat.

I then trim them dry and jar them, opening and closing until perfect to my liking.

I got a lot of this drying technique from a DJ Short article (if my memory serves me correctly), except that he recommended brown paper bags for the wet/dry, the garbage bags and whole plants are my idea.

I realize this only works for personal growing and not commercial (too labor intensive), and for small/medium sized plants (hard to fit a plant over 3' tall in a contractor bag).

I grew recklessly for almost 2 decades before i started practicing this, and for the last decade since, my smoke has doubled in quality IMO....

 

[CrushnYuba]

I totally buy it. Cool dry runs are always better quality but significantly lower yields. Seems like more trichomes to plant material. There is definitely less terpine evaporation and more stank to it.

 

[Gone Camping]

Definitely subbed for this discussion.. I look fwd to the education.

Thanks @Douglas.Curtis, appreciate the time you took to share.. i'v found your posts to be very informative.

 

[Bobby Boucher]

I've never seen your weed, Doug, but the most terpene rich smoke I've ever seen was always grown hot and humid, consistently for 15 years or so now.

Lets just say, with a proper ph swing, and nutrient management.. hot or cold.. dry or humid.. you get buds that beat out the competitions.

Maybe "cold and dry" beats out "hot and humid", but if you think hot and humid would disqualify weed from being rich in smells and flavors, you've just never met the right grower.

And if you are trying to strike vpd from the record... I simply don't know how to respond to that.

More likely that each cultivar would respond better in its natural habitat which it acclimated to over millennia.

 

[blazeoneup]

It only aids in terpene retention when there is terpenes to retain, running reduced temperature and humidity during the veg cycle and all of flower is just slowing down the growth rates for no true benefit IMO.

Reducing temperature and humidity from week 5 or 6 flower through the dry/cure however does help retain terpene. Some peoples plants grow richer in terpene based on the methods used and hence don't need reduced temps to retain as much or more.

If you want to maximize terpene production and overall trichome production give potassium silicate a shot, It also thickens the wax layer of the trichome which also helps with terpene retention and imo allows the plants to naturally hold more terpene.

You combine that with reduced temperature and humidity from week 6 on through the dry and cure and you will see some of the most flavorful longest shelf life nuggets you can get really.

I've rolled joints of straight sugar leafs and smoked with guys and had them all fascinated at the flavor and after I told them it's pure leaf they argued no fucking way possible. Throw a bag of sugar leafs on the table and tell them to roll up and the looks on their faces when they realize it actually is leaf they were smoking.....

When I crack a jar the smell fills the room.

Katsu Bubba Kush

Deathstar

Old Family Purple

Cookies

 

[Douglas.Curtis]

Greatly appreciate the civil discussion everyone, and thank you for contributing. I know diplomacy is not my best skill at times, and these threads are helping. My focus is on being clear enough in my information sharing.

I've rolled joints of straight sugar leafs and smoked with guys and had them all fascinated at the flavor and after I told them it's pure leaf they argued no fucking way possible. Throw a bag of sugar leafs on the table and tell them to roll up and the looks on their faces when they realize it actually is leaf they were smoking.....

When I crack a jar the smell fills the room.

Beautiful flowers, thanks for sharing. This is the kind of quality I'm talking about, yes. I can definitely taste the difference, but everyone else will have no idea it's simply frosty leaf.

It only aids in terpene retention when there is terpenes to retain, running reduced temperature and humidity during the veg cycle and all of flower is just slowing down the growth rates for no true benefit IMO.

Reducing temperature and humidity from week 5 or 6 flower through the dry/cure however does help retain terpene. Some peoples plants grow richer in terpene based on the methods used and hence don't need reduced temps to retain as much or more.

When I crush a flower there is a single stem, the rest is frosty flower bits. I believe the structural differences formed during 5-6 weeks of hot/wet flower production are sub-optimal. Extra stem and plant content are being grown under the same trichome count. What appears frosty can be so much more dense.

This 5-6 week period is also removing complexity to the end terpene profile. I understand polymerization creates complex terpenes from monoterpenes. The longer monoterpenes are present, the greater their chances of polymerizing into longer chain terpenes. When complex enough, they become terpenes you can still taste 45 minutes after smoking a joint. I believe this is one reason growers don't recognize their own clone when it's grown cool/dry. The presence of monoterpenes which vaporize off at the 70F+ temps are not available for polymerization, but they do make the room smell nice.

Potassium silicate is definitely beneficial, and it's something I've been using for years now. Thanks for bringing it up. As with almost everything else with cannabis, less is often more.



(Edit I believe a very close analogy is the difference between growing grapes for the table and for wine. Table grapes are a bumper crop of fat and juicy grapes. The same variety of grape grown for wine, is grown significantly smaller, has a much lower yield per acre, and ends up with significantly more flavor and complexity. The premier information on producing cannabis is for table grape quality cannabis, which is definitely bountiful and tasty. Personally though, I'm looking for much more complexity and flavor, so the process is more like growing grapes for wine.

 

[imakandi]

(Edit I believe a very close analogy is the difference between growing grapes for the table and for wine. Table grapes are a bumper crop of fat and juicy grapes. The same variety of grape grown for wine, is grown significantly smaller, has a much lower yield per acre, and ends up with significantly more flavor and complexity. The premier information on producing cannabis is for table grape quality cannabis, which is definitely bountiful and tasty. Personally though, I'm looking for much more complexity and flavor, so the process is more like growing grapes for wine.

this is offence
to any grape grower
you obvious not grape grower,

i say before, open mind,
but like some proof,
so far, only picture of little bud, no diary, no science, no fact
lot of write

but is free forum

 

[blazeoneup]

Greatly appreciate the civil discussion everyone, and thank you for contributing. I know diplomacy is not my best skill at times, and these threads are helping. My focus is on being clear enough in my information sharing.


Beautiful flowers, thanks for sharing. This is the kind of quality I'm talking about, yes. I can definitely taste the difference, but everyone else will have no idea it's simply frosty leaf.


When I crush a flower there is a single stem, the rest is frosty flower bits. I believe the structural differences formed during 5-6 weeks of hot/wet flower production are sub-optimal. Extra stem and plant content are being grown under the same trichome count. What appears frosty can be so much more dense.

This 5-6 week period is also removing complexity to the end terpene profile. I understand polymerization creates complex terpenes from monoterpenes. The longer monoterpenes are present, the greater their chances of polymerizing into longer chain terpenes. When complex enough, they become terpenes you can still taste 45 minutes after smoking a joint. I believe this is one reason growers don't recognize their own clone when it's grown cool/dry. The presence of monoterpenes which vaporize off at the 70F+ temps are not available for polymerization, but they do make the room smell nice.

Potassium silicate is definitely beneficial, and it's something I've been using for years now. Thanks for bringing it up. As with almost everything else with cannabis, less is often more.



(Edit I believe a very close analogy is the difference between growing grapes for the table and for wine. Table grapes are a bumper crop of fat and juicy grapes. The same variety of grape grown for wine, is grown significantly smaller, has a much lower yield per acre, and ends up with significantly more flavor and complexity. The premier information on producing cannabis is for table grape quality cannabis, which is definitely bountiful and tasty. Personally though, I'm looking for much more complexity and flavor, so the process is more like growing grapes for wine.

I like confidence, I'd love to do a product comparison and see who really has the grapes worthy of fine wine. I've been at it over 20 years myself and I've grown in every environmental conditions between 65f and 90f 25% humidity to 80%. I've tested all these different environmental settings on full cycles to figure out what works best for me. I spent countless time and energy figuring out how to produce the best product I can. I know for sure my products fine wine! My thoughts are you might have a great product it might be worthy but mine is too.

I think based on my own experience you would find that my method produces a worthy end product. Basically I'd love to do a product comparison because I love confidence and more importantly I love artisan flower...

EDIT

I hope that doesn't sound confrontational I don't mean it in a harsh or negative manner, I am simply stating I put in the time to figure out what produces the upmost quality for me. And for me the method I outlined produces superior product than a low temp low humidity from start to finish. That's not to say your low temp dry climate doesn't do the same for you.

 

[siftedunity]

i can understand that something maybe lost at higher humid temperatures, on the other hand, if the plant is developing so slowly because of low temps and rh, surely its also going to produce less of those said terpenes etc in the first place.. I think the general consensus is to start hot and humid, replicating natural conditions, then to reduce temps and rh to mimic nature and to preserve quality. seems like at cool low rh, something has got to be compromised and not just yield.. same as how keeping rh and temps high throughout till harvest would also compromise quality

 

[Bobby Boucher]

I'm just going to throw this out there..

Dude always ran his exhaust on a timer.

I've speculated for years that swings in rh and temp every hour.. as dude always set it.. or perhaps even regular intervals or negative and neutral pressures.. might also have positive effects on the plant, in regards to smells and flavors.

Because.. wow. Dude could take any strain and turn it into something that was absolutely twice as chocked full of flavors and smells than anything I'd ever seen, save for some comparable og buds I seen outa socal, and a jillybean I saw from michigan.

His nutrient management sounded much like yours, but he grew hot and humid af. Tents get hot and humid with an exhaust on a timer like that..

And his yields were outstanding.

 

[Douglas.Curtis]

Great stuff, thank you.

I firmly believe we have a bunch of 1%'rs on icmag. Figuring about 1% or less of the cannabis on the planet is grown properly. I -Know- some of you produce better quality than I do, even when scored using my own standards for 'quality.' It's simply so rare most growers have not experienced it yet.

It's this type of discussion which brings out the details I love most, and ultimately ends up producing the most positive results.

 

[siftedunity]

or possibly what you find to be amazing quality is different to what other people would consider amazing quality.

 

[White Beard]

I like your posts, Douglas, they always stimulate my thinking. I appreciate that.

 

[Chevy cHaze]

Douglas,
What about the quality of the light? I read a couple times on the sativa heavy reports here, that cold blue or white lights some of which even had added extra UV was the best lighting to grow in colder temps and to get out plant expressions normally hidden.
What are you using?
I'm currently at 23C day/ 17C night under a MArs T1000, but not as part of my master plan-- it's just a bit cold up here atm hahaha.
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