Dark period before harvest – how long?

Beautiful work! I cut early after an overnight dark, but that is convenient for me as much as any other reason.

Harvest a few hours before lights turns off, Before the sugars that have been photosynthesized, during the light period, sinks to the roots to feed the bacteria when lights goes off. Sugars moves from SOURCES to SINKS. This is called the Pressure Flow Hypothesis. Buds are one of the sugars sources. This is one of the technics used to make candy buds with a high sugar content tasting very sweet. (PS: Source for the binary garden dwarf) Georgia Institute of Technology : https://organismalbio.biosci.gatech.edu/nutrition-transport-and-homeostasis/plant-transport-processes-ii/

Majority of terps and trichs are processed at night when the plants oxidative capacity is free and available to work. Mornings are always the best time for any harvest because of this. No if ands or buts. Dark period is a point of contention and is grossly misunserstood in its purpose. 48-72 hours of complete darkness is a biological signal trigger that initiates a response from the plant that potentially increases the release of enzymes that assist in the accelerated degradation of chlorophyll right before harvest. Essentially initiating "PCD" Programmed cell death. How much it helps? Is arbitrary, in my opinion every 0.25% is worth it. On that note I wouldn't worry about it. Plant autophagy is a well-documented, conserved, and essential component of plant biology, functioning as a major intracellular degradation and recycling system that maintains cellular homeostasis. But grandmaster guru cannabis cultivators call it BS without a 2nd thought. Whether people want to misconstrue its use is entirely up to them. Ignorance is bliss. Rather than do darkness do excess "blue light" for last week of ripening, replacing full spectrum with 5k+. This gives her a little boost. Signals increase in smellies. Works well from my experience. Best o luck those trichs look amazing 👏. Don't need anyone's advice!

In my experience the dark period before harvest doesn’t make a big difference. Some growers give 24–48h darkness, but there’s no strong evidence it increases potency or terpenes. I usually keep the normal light cycle and harvest right before lights would turn on, since terpene levels are often highest then.

Extended darkness is BS. Chop about one hour after lights on and with a normal light cycle. Works for me for decades already. A plant in darkness can not function. A plant that is not functioning can not support health. There is no magical way to alter anything in a few hours that has taken weeks to develop. Have done many, many experiments over the years and like I said, extended darkness is BS imo............just like the supposed benefits of molasses.

Hey, this is a question that really divides the growing community! This technique, often called the "pre-harvest dark period" (usually 48 to 72 hours), is based on a few theories but is not an absolute requirement. Here’s a summary to help you decide: Why do some people do it? (Theoretical advantages) The idea is to stress the plant one last time to "boost" its final production: Resin production: It’s believed that the plant, feeling like it’s dying, produces one last spike of trichomes and resin to protect its seeds (even if there aren’t any). Preservation of terpenes: Terpenes (which give the smell and taste) are volatile and degrade in light and heat. Total darkness and cooler temperatures would help preserve them as much as possible just before cutting. Starch degradation: Without light, the plant consumes its sugar and starch reserves, which would make the smoke smoother and less "green" in taste. Why do others not do it? (The reality) Mold risk: This is the main danger. If your humidity level is high (above 50-55%) and there’s no light to heat the air, moisture can stagnate in dense buds and cause rot (botrytis). Limited scientific evidence: There are no definitive studies proving that 48 hours of darkness radically changes THC levels. Many pro growers prefer to simply cut the plant at dawn, when the concentration of terpenes is highest. My "safety" advice If you decide to do it: Check the humidity: Keep an active air extraction and make sure the air circulates well. Duration: Don’t exceed 48 hours. Beyond that, the risk of mold outweighs the benefits. The alternative: If you’re worried about mold, just cut your plant right before the light turns on (or at sunrise). That’s when the plant is most "loaded" with good stuff. Important note: Don’t forget that the most important factor for final quality remains the flushing (watering with clear water for the last 10-14 days) and especially a slow drying process.

Doesn't have a measurable effect, and any negative effect will be imperceivable. Do whatever floats your boat. Can't argue with magic. I've read you should harvest before lights come on, but not sure if that was based on anything real or just more anecdote. Years ago i would turn off the light timer the night before a harvest, but nowadays i grow 8 plants at a time and not going to interrupt the dark cycle of the other plants. Years of doing both and i cannot tell a difference. So, even if there is a measurable statstically significant effect, It must be incredibly small and irrelevant. Just because soemthing has a measurable effect or correlation doesn't mean human senses can notice a difference or that the effect is profound and worthwhile to be of concern. That's a seperate question for each context you look at. For example, blue and red wavelengths have measurable and real effects on plant morphology that i will never debate, but it will never turn a short, squat plant into a stretched out plant, for example. Half my room is 2900K half is 3400k and again... relative to genetic diversity it is impossible to recognize the difference they have on plant morphology. i could assume things, but I have short plants under the red-heavy light and i have lanky plants under the blue-heavy light -- it's signifcantly more about genetics than the CCT of the light above them. Maybe, if i did a room full of clones i'd notice 'something,' but it'd still be a small effect. Use such things to your advantage when possible, but of little concern if you cannot. I.E. If i could see the future, i'd put the short plants on the red side and the tall plants on the blue side, but ... I do not have powers of foresight, lol. Once they grow through the scrog, which has a profoundly more beneficial effect, the plants don't move around.

You don't need to go through the 48 hours of darkness; it's pointless. Harvest before the lights come on.

You could do the opposite and go for 48 Hours of light like Prof. Bugbee suggested. That might do something. The effects will be negligible in any case ether way.

the only trick here is to harvest in the dark period, with any changes to the natural rhythm you have already set the leading weeks being meaningless to the plant. this is, in fact, known if i took you said now you work 3rd shift instead of 1st shift, you will take days to weeks to acclimate on a physiological level...she is the same. you can see this based on EC metrics over time in hydro solutions at night relative to day; for the same reason you harvest when the most free salts have been exchanged downward into root mass. roughly 3 hours into dark until roughly 3 hours before light is your sweet spot, trading salt uptake into the plant mass from roots increasing for nominal trichome repair increase... both of these are things that are on 24 hour time cycles anyway... doing for example 48 hours of random darkness for the plant at the end of an established photoperiod has been categorically shown to be a nothing-burger. watching EC over time shows that the plant still behaves (for days to weeks later) as if the original schedule was true still

I had times doing the dark-period-before-harvest-time, but I chose science over bro-science. And science can sometimes be very easy: Without light a plant can not doing photosynthesis. With the motor off, you do not get any benefits from/for your plant. Or at least not more benefits than from harvesting before the light go on in your usual light-schedule. To harvest before lights go on is very common among growers cause a part of the terps get lost the longer the day.

I AM NOT DAT PICKY!!! MOST TIMES I CHOP WHEN ITS CONVENIENT FOR DA HINDUGOD!!!! 85% OF DA TIME DAT IS JUST BEFORE DA LIGHTS TURN ON!!!!

I like to give 48 hrs dark.. This can't be proven, some would say it's broscience I say 🖕

I chop them down after 24 hours of darkness some go for 4 days. I tried 4 days ending up with dry stems and partially dried buds, I didn't water the plant so the roots pulled al the moisture from the plant. So if you go for longer than 24 hours keep watching for dry soil. You did a good job there Rocks cheers.