I’ve done some reading about light degrading the resin and terpines in the flower which are replenished during the night so it’s believed weed is stronger if given extended darkness just before harvest (48-72hrs)…does anyone have any experience with longer time frame…this evening will be 48 hrs for mine. If I don’t harvest this evening I won’t be able to until Sunday afternoon which will be around 100hr+ of darkness…is this something I should be concerned with?
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I haven’t seen many growers that subscribe to the dark period before harvest theory and I’m not aware of any legitimate research that points to it being effective. I’ve never done it and am skeptical that the practice actually helps. Other forums tout it, but it’s not a common practice among most of the growers here.
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@Tegridypharm Check out this video for an in depth scientific explanation of why a dark period isn’t helpful to the harvest.
Dr. Bruce Bugbee interview with Mr. Grow it
https://youtu.be/W-3ZZJyk5lc
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The line in the video that catches my attention is “If we take away the light from a plant, we take away the plant’s energy source to produce terpines.”
I’d still like to see research, but it would be hard to do given the individual phenotype variations we see. The researcher would have to use clones and have very rigid grow parameters. That said, Bugbee is probably as good as any authority out there on the subject. He has a lot of credibility in the growing community.
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Harvest away. That’s bro science.
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The common line of thinking now days about lights out before harvest is slowly becoming bro science in many peoples minds eye. Same with massive flushing and other actions done at harvest time. I’ve been doing 48 hrs of dark before chop for decades. Next harvest I’m just going to let the plants go through there normal dark cycle and harvest the next morning. And I’m not going to flush them hard before harvest either. It’s not that I fall on one side or the other concerning the idea’s/science. It’s basically I getting pretty fed up with all the BS concerning growing weed now days and all the near worthless crap hybrid crap fufu weed that seems to be the rage now days that I can’t seem to get stoned on unless I concentrate or turn into edibles. It’s starting to turn into a pain in the ass for a lower quality product IMHO.
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If the plants started putting out pistils the day after I flipped to 12/12 I might be inclined to believe it, but as we all know there’s a “transition” time between the flip and flowers forming. Why would this action have immediate effects on a plant when that one doesn’t?
If someone wants to go dark for 10-14 days, which seems like an average length of time for the plant to move from one phase to the other, as demonstrated by flipping to flower and the average seedling period being about 2 weeks, then I’d be interested to hear the results.
I can guarantee there will be a difference in the buds after 10 days of darkness.
Not sure you’re gonna be happy though! 
Maybe THC is increased when the mold spores start to form clumps and grow on the buds because 24-48hrs of a dark, warm and moist environment is all it takes to start growing black mold?
I’ll pass on those chances thank you very much!
It’s like the “no nutes before harvest” thinking. In side by side comparisons the starved weed comes in second to the fed weed for taste and potency.
THC is a product of resin. The plant produces resin for several reasons, one being protection from the harsh rays of the late summer sun. It seems to me that 24-48hrs of INTENSE light might make for better THC quality vrs a procedure that in no way naturally corresponds to why a plant does what it does.
I mean - does the plant produce excessive THC containing resin to protect it from the moon in nature?
The correct answer is “No”.
Not sure if I’d do 48hrs of lights on and really screw up the circadian rhythms of the plant at the end but perhaps cranking the light to the highest setting and literally blasting the living shit out of it for the last few days, while still sticking to the on/off schedule, might produce a more resinous, THC covered plant.
I wonder if anyone has ever tried that? I can’t generally run my HLGs at 100% at any time during the grow without risking light burn or adverse effects.
More intense light = more resin. It’s just the way the plant works and i don’t think our will alone is enough to make it, or anything for that matter, change.
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Well said, the resin is also produced to deter pests, gives mold resistantance, sunblock as your said. I tried leaving the lights on 24hrs before i harvested last grow and one plant grew banana’s very quickly due to the added stress. Uggh! 
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I’ve done 24,36 and 48 hours of dark before harvest and didn’t notice any difference in the finished product.
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What did you compare the dark time buds to? Did you leave some plants on 12/12 as a control?
@Tegridypharm I know someone who practices this style @merlin44 may be able to offer you his thoughts. He has one in darkness for todays/tomorrow’s chop currently I believe.
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No, I didn’t just from trying same strains when I harvested ones without darkness compared to dark period.
As @Fieldofdreams said, I take the plants out of the room for about 24 hours before chopping. I don’t know if it has a positive effect or not. It certainly does no harm and it costs me nothing.
Longer than a couple of days of darkness may be harmful, do don’t know.
@Tegridypharm @Blastfact I agree that there is a lot of urban myth out there regarding cannabis cultivation. There is also a lot of excellent information that is verifiable. The trick is to figure out which is which.
I don’t flush before harvest but I do stop actively feeding them about a week or so before chopping as there is very little going at that late stage of the plant’s life.
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It takes weeks and weeks for the plant to fully ripen. Nothing you do in 24-48 hours is going to have any noticeable effect…
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I chopped them down tonight…I guess I should have clarified…I wasnt attempting four days of darkness to strengthen the pot further. I am going out of town for the weekend and if I didn’t cut them now it would be Sunday before I get back to them. This is only my third grow…first time trying the darkness before harvest.
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