Length of Dark Time before harvest

[RetiredGuy]

I am going to be pulling three of my plants from my grow closet later today and will put them in a dark space until I harvest.

How much dark time do you feel is optimum before chopping or do you think it matters? I have read elsewhere that up to 72 hrs can improve the amount of resin and would like to hear your opinions. Thanks in advance!

[GuitboxTom]

Dr. Bugbee, cannabis research at USU, states that darkness before harvest has not shown to be of benefit unless that means cooler temps as a result. So what he is saying is regular light schedule right up to harvest and lower temps in the dark periods. Which is most like nature. So I’ve used ice water flushes to accomplish the temp drop. Does it improve resin levels? IDK! But it won’t kill them even of done for several days.

[RetiredGuy]

Thanks, I have watched some of Dr Bugbee’s stuff on YouTube.

[OldManGrower]

Veeery Interesting. First I ever heard of doing this. I may give this some consideration.

[Going2fast]

I call bro science on this. If it isn't potent enough beforehand 3 days of darkness isn't going to make it better.

[golfnrl]

I've not tried the dark period...I've read a lot about it but haven't been convinced it's worth a try because of the 'possibility' that it might be of benefit. So far I've learned along the way that everything that might help also might not.

[GuitboxTom]

https://youtu.be/W-3ZZJyk5lc

Bugbee interview.

[BU2B]

GuitboxTom Thank you. Very useful information. Much appreciated. 👍🏼
Actual evidence is ALWAYS better than anecdotal evidence. Thanks to you providing something more than words to back up your opinion (which is based on fact); for the first time in years I WONT be adding a dark period prior to my upcoming harvest and will instead focus on cooler temps.

[3Berries]

I did this one time and the plant was full of stickyness all the way down the trunk. Did it a second time and it didn't do that. Difference was time of year, cooler temperature with the stickier one being wintertime.

Got one to pick today and was wondering how to keep it in the dark without molding. I have a room that's running 60%RH right now, rest of the house is around 75%. I had bud rot develop on a cut one hanging at 70%.

I'm thinking a garbage bag with vent holes in the top and a little fan blowing up from the bottom while it's still in the pot for 3 days.

[GuitboxTom]

In my experience, which I’ll admit is limited with indoor grows, use of a plastic bag can cause bud rot. I’d prefer a vented cardboard box.

[GuitboxTom]

GuitboxTom Thank you. Very useful information. Much appreciated. 👍🏼
Actual evidence is ALWAYS better than anecdotal evidence. Thanks to you providing something more than words to back up your opinion (which is based on fact); for the first time in years I WONT be adding a dark period prior to my upcoming harvest and will instead focus on cooler temps.

BU2B , now on Sunday Nebula reported increased THC content after 3day darkness compared to no darkness with buds from the same plant. So not to draw conclusions she is planning more experimentation. Tracking temp differences and using clones. Presently, I’m going with 1 or 2 ice water flush’s. I can’t get the temp down in my tent even with the lights removed it’s 81F with exhaust and 1 indirect fan for drying. Also pushing to get the RH up to 52% haven’t got tot 60% yet but I think I can by tonight.

[SoOrbudgal]

I read that also GuitboxTom I've not really done it for 3days could'nt take it LOL but i believe it's possible?

[BU2B]

I believe Nebula's 'one case' study had an increase of exactly 10% THC. The debate was actually over the illusive article that claimed up to 30% increase. 10% is nice and nothing to poo poo at, but for now, I will stick with the fact that cooler temps during flowering also appear to increase terpene production as well as THC. I don't think an extra three days of darkness is going to hurt your plant(s) or lower their THC values - I'll stick by that much of my original statement and also think it has the potential to raise THC content, maybe a combination of the two would be best; I really don't know. Nebula's findings are promising, but not conclusive and I'm looking forward to seeing any further developments. However; unlike our esteemed founder, I haven't the time, money or resources to experiment to that degree and really NEED the medication that cannabis provides on a reliable basis and not 2.5 hour one way trip to the dispensary hope you have the money in the bank reliable way.

[3Berries]

Day three of darkness. I cut a bag open and it's just laying on top and the side that is exposed to any light.. Probably cut it tomorrow.

[GuitboxTom]

Well I just threw in the towel on my NLights auto. Ice water flushed and in the dark for 3 days. Still seeing some clear trichs, but just a few amber. It’s hard to look at. Left it too close behind our outdoor fire place and my wife decided to burn papers so it got scorched on the side of 2 colas.so we’ll see if the 3 dark days does anything for this basket case.

[3Berries]

Just cut and trimmed and ready for drying. For what it's worth it does defiantly get stickier all over. And the leaves appear to continue to grow somewhat. Defiantly not a dead plant.

Temps and humidity were upper 70s.

[GuitboxTom]

BU2B right on! Although a 10% increase is an ample amount of THC. I’m more interested in high CBD as well. Still great to have someone like Nebula who is willing to put the resources into such research. One thing I’m wondering is; how does the 3 extra days of grow time even in darkness effect the results. So, in an experiment, do you let the second identical clone grow while the other one goes dark for the 3 days, then chop both? IDK we’ll have to see. I can think of several experiments on this. Seems to me that if you’re looking for amber then the THC would be diminishing somewhat over those three days?

[BU2B]

as mentioned by GroBuddy degradation is a natural process and continues even after the flowers are harvested. The premise is simply this: Light degrades trichomes (fact), Trichome production happens mainly in the dark ( debatable fact. If this is ALWAYS the case how do autos with a 24/7 light cycle achieve THC potency?), 3 days of darkness allows trichomes to form without light degradation therefore increasing overall THC values (this is the debate). A 10+ year old article from Denmark claimed up to 30% increase - quotes can be found from this article that do align with given facts at the time. The article in question however seems to have disappeared but strangely the quotes remain, leaving some question about the papers origin or if it ever existed at all or is simply another 'bro science' falsity. To the best of my knowledge NebulaHaze 's grow; which was tested, is the first actual evidence in investigating of this supposed phenomena and at this point, the first hand tested evidence does indeed support the claim of at least marginally increasing THC values of your harvest. One also has to keep the evidence that cooler temps increase terpene production as well as THC and that there are more than 60 cannabinoids in play as well. Ask anyone who's smoked THCa crystals without some terpenes and you will quickly find that there's more to a good HIGH than high THC. I'm a true believer (based on evidence and personal experience) in the entourage effect.

[GroBuddy]

It takes time for trichomes to develop they dont just appear and go cloudy over a 2wk time. Idk how dark increases thc 10% if there wont even be enough time for trichomes to ripen before jarred. Plants deteriorate after harvest not continually mature. Why so much goes into dry and cure to preserve rather deteriorate

Theres also studies that show other broscience truths that should be taken with a grain of salt. Like flushing, transplanting autos, etc.

[SoOrbudgal]

I do believe there are certain circumstances that calls for flushing and me personally do transplant all of my strains successfully. Not bragging just that i've never lost a plant to transplanting. I don't think that leaving a living plant in the dark for 3 days in the pot is bad. Too each their own.

[GroBuddy]

Theres never any reason to flush, anything can be fixed with time. Especially using liquid nutrients giving a 20% runoff. That's a mini flush every watering/feed.

I agree it's not bad, also not necessary. My first 4 or 5 grows I did that 48hr darkness bs didn't see, taste, or feel a difference in finished bud

[3Berries]

I should have scoped my buds after the three nights of dakness. Trimmed and hanging right now. Super sticky. Showing 59% on a sensor hidden in the stalks. Need to move it to a more humid room for a couple days more. Getting too dry in the dry room.

[GuitboxTom]

BU2B , thanks for the interesting reply. Good info as always. Also your PPP method is very interesting. Great work, thanks. I’ll try it next grow. Just to report, I did put my NLights auto in 3 days darkness and ice flush, after which! I had maybe 5% amber but still some clear and headless trichs. It’s chopped, bud washed and hanging in 55-61% RH and 75-80’F.