24 hrs. in the dark?

I have heard that the last day before harvest you should keep your lights off for 24 hrs. and someone even said up to three days. What is the purpose of doing this? Does it make the plant go into overdrive and make a last ditch effort of getting bigger? Anyone ever do this?

People have been discussing this for a long time.
I personally don't use dark periods, people who do, claim that the calyxes swell even more, that trichome production is pushed up and that the weed just generally improves.
Some people also combine a dark period with a 'no-water' period, thereby sort of drying the weed, making it easier to harvest and dry properly.

I have never seen any real studies confirming or denying this though, therefore it's more of a judgement call than anything.

Thanks for the info k0ijn. Sounds like I should research this a little bit more. It sounds like it is possible, but as you said, there is no clear cut evidence showing one way or the other. I'd like to hear from people who do this. How long do you keep your plants in the dark before harvesting, and what effect does it have on them? I wonder if the Admins would create a whole separate forum that is strictly for nothing but research. I'd like to be able to do my own research and testing on plants and post any results that I may have. For instance, I have always been curious about grafting. What happens when you graft a plant? Is it the same as cross breeding two separate strains? What happens if you graft a female top onto a male bottom, will it eventually turn hermie, will it stay female? O.K. maybe I'm going too far, but I still have tons of ideas I'd like to research.

ya....ppl say that darkness builds resin........but just as many ppl say it doesnt help what-so-ever

Does anyone have a link to a thread confirming or denying this? +rep

In night or darkness stage, the plant starts focusing on root development. If you stop watering the plant and give it enough time in the dark, it will drain the plant of a large amount of moisture.. But I recommend drying upside-down, so the THC and remaining moisture makes its way through the plant, making it more potent.

the dark period helps in resin production, just not what some people expect... and its nothing remarkable.

used i conjunction with a few other techniques however, you can see a noticable increase.
ice water feedings, bending/breaking branches. anything to stress them basically.

its really just to get that extra kick from your bud. doesnt increase yields.

Thanks for all of the info.

It's free. And easy and a nice 3 day break before the worst part of the process so I do it. I hate trimming

Edit: Quoted from p77 Jorge's Indoor/outoor med bible: (latest version, Copyright 2006)

"Growth stops at harvest, and the THC content cannot increase. It will stay the same, or decrease after harvest"
and

"Growers hang plants upside down because it is simple, convenient, and effective- not to 'drain existing THC-potent resin into the buds."
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Hanging the entire plant upside down does nothing, its just an old myth (source Jorge Cervantes' book). It likely came about because that is how some cannabis producing countries have traditionally dried theirs.

As for the "24h+ dark period" I've tried it and all I can confirm with 100% certainty is that it makes trimming much harder. It is easiest to trim fresh plants that are still "alive" and crisp. If you let one sit for day/s in the dark, or over-water it, or whatever people are trying these days, then the leaves get all droopy as the plant starts to die, this will result in a plant that is a bitch to trim. Also, it slows down your production.
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I normally just lurk, but I thought this was important to mention.

Thats some great info Smoke. Glad to see someone on here debunking these myths. I think we need more of that.

well for you asking about a thread with proof, there is none just opinions, i dont think anyone has officially tested it

Did three days of dark last grow. this grow I'm not gonna do it just to compare. I personally think trichome production is at its max just do to my uvb lamp. cant see dark improving it much