15 hour flowering period

KLITE

KLITE

Well-Known Member
Hi all

Recently when speaking to a reputable master grower he tells me he flowers all his indicas and mostly indica hybrids by flipping the switch to 15 hours of light until plant finishes the inital flowering stretch until 3rd or 4th week and only then switch to 12 hours. Says plants usually take a week longer to finish but yield a heck of a lot more.
Any one has any experience with this?
 
AfgooCBD

AfgooCBD

Well-Known Member
I went from 18/6 to 14/10 for 7 days, and no change in growth (veg) compared to 18/6. Didn't notice any kind of crazy stretching starting. Switched to 12/12 on Day 8, and in one day, plant skyrocketed in growth, an inch or two in one day, all branches. Same lights (blue). Maybe it took a week for the plant to figure out the days were getting shorter? Maybe because it had a longer dark period that night? Who knows.

You would have to do an experiment to know for sure if it would yield more, IMO. 18/6...12/12 compared to 18/6...15/9...12/12. I think if anything it would be less stressful on the plant doing the latter. Whether that produces more yield in the end? Maybe. Maybe not. I think it's more just personal preference on how a grower wants to switch to 12/12.
:peace:
 
T

tomb805

Active Member
I went to a di short breeding and genetics class up in Ann Arbour last week and he suggests that everyone should do a 11 light and 13 Hour darkness for flower.... he said it doesn't seem like a huge difference but the plant does notice... he said your buds Will be thicker and bigger and stronger.... plus at harvest outdoor the nights are longer than day... not an even 12/12... I figure it won't hurt to try which I am going to see next harvest...
 
C

churchhaze

Well-Known Member
This might work if you end the day with a pulse of 730nm far-red light to put it to sleep faster.

730nm light will convert the majority of Pfr to Pr, the inactive state of phytochrome faster than darkness alone, giving you up to 2 extra hours of effective night length.
 
C

churchhaze

Well-Known Member
A lot of people use the 730nm pulse trick in the LED section here now with good results.

1) earlier flower onset
2) finishes flowering about a week earlier than without the far-red pulses.
 
Cannasutraorganics

Cannasutraorganics

Well-Known Member
KLITE said:
Hi all

Recently when speaking to a reputable master grower he tells me he flowers all his indicas and mostly indica hybrids by flipping the switch to 15 hours of light until plant finishes the inital flowering stretch until 3rd or 4th week and only then switch to 12 hours. Says plants usually take a week longer to finish but yield a heck of a lot more.
Any one has any experience with this?
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He is probably running 20/4 on veg. It works. Not willing to push to 15, but 14 I've done. 3 weeks then 12/12 3 weeks and last 2 weeks 10/14.
Looking forward to switching to DE with computer control of ballasts in the next year or so. Can write a program to start at 14 and go down to 10 in even increments like outside and turning 1000 on at 600 and ratcheting up to 1000 then for 3 hours in the middle go to 1150. Then last two hours roll back to 600 slowly.
 
KLITE

KLITE

Well-Known Member
He is probably running 20/4 on veg. It works. Not willing to push to 15, but 14 I've done. 3 weeks then 12/12 3 weeks and last 2 weeks 10/14.
Looking forward to switching to DE with computer control of ballasts in the next year or so. Can write a program to start at 14 and go down to 10 in even increments like outside and turning 1000 on at 600 and ratcheting up to 1000 then for 3 hours in the middle go to 1150. Then last two hours roll back to 600 slowly.
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How did you find it worked for you having them 3 different photoperiods? I dont think id go below 12 in indicas for much more than a week. TRhge main claim the guy made is you get bigger yields.
I too have had the idea of somehow incrememnting and decrementing light itensity with the photperiods course, but more in those stoned dreamy moments. Itd be cool as fuck to make that happen. congrats!
I am willing to give a 14 or 15 hours period for the first few weeks a try though kinda wanted to hear if anyone had messed with it.
 
GroErr

GroErr

Well-Known Member
polo the don said:
@GroErr does something like your talking about.
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Yeah, I try when possible (room/lights available) to go from my normal veg lights schedule (18/6) to 14/10 for 7-10 days before going into flowering. 14/10 stretches them and gets them pre-flowering, when they reach the main flower room @12/12 they're 90% stretched and ready to pop flowers. I like them pre-stretched because I know what size they're going to be when they reach 12/12 as they're pretty well finished stretching. I trellis them at that point and can shape the footprint and canopy where I want it to be. Because they start pre-flowering at that 14/10 stage, last couple of times I did this, I was seeing flowers within 3-4 days of hitting 12/12. I like this method for my style grow but can't always do it, running offset perpetual runs with 2 lights means my veg cabinet is always full with plants at different stages.
 
KLITE

KLITE

Well-Known Member
@GroErr Man thanks for your input.
The guy who spoke to me about it i know for a fact he knows hes shit cause hes in charge of a bigger grow than me but we didnt speak for long. He made me feel that the after 3 or 4 weeks at 14/10 the plant will stop stretching and begin to want to pack on flowers, this is the crucial moment when 12/12 should be implemented. He also said that if 12/12 is put in effect a bit too early or too later from the time the plant stops the stretch and starts packing it the plant can sufffer a little stress. He also said plants will create bud sites under 14/10 at like week 2 and when these start growing in volume, or actually a day before you think they going to start putting volume you flip.
 
GroErr

GroErr

Well-Known Member
KLITE said:
@GroErr Man thanks for your input.
The guy who spoke to me about it i know for a fact he knows hes shit cause hes in charge of a bigger grow than me but we didnt speak for long. He made me feel that the after 3 or 4 weeks at 14/10 the plant will stop stretching and begin to want to pack on flowers, this is the crucial moment when 12/12 should be implemented. He also said that if 12/12 is put in effect a bit too early or too later from the time the plant stops the stretch and starts packing it the plant can sufffer a little stress. He also said plants will create bud sites under 14/10 at like week 2 and when these start growing in volume, or actually a day before you think they going to start putting volume you flip.
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Interesting, never tried running them that long @14/10. Most I've gone I think was 12 days and that was the first time I did it, funny thing is that it was unintentional, my flower room needed some finishing touches to be ready and I decided to reduce them but not induce flowering, kind of a mistake really. Then I noticed the significant stretch (good as I tend to grow short/fat/dense bushes) and quick flowering time as soon as I flipped them to 12/12. Replicated that and have tried to use this method since then.

For my purpose, to get them pre-flowering/sexed and stretch them, 8-12 days works well and typically the main stretch period when flipping straight to 12/12. Having them @14/10 for 3-4 weeks would eventually begin flowering but I'd question the practice as imo it would increase total flowering time by a week or two. With 8-12 days @14/10 I've seen flowers pop up as soon as 3 days into 12/12. Not a huge difference between that and a straight flip into 12/12, could even speed things up but haven't tracked it closely enough to test that though. You'd have to try different lengths @14/10 with the same strain to find the sweet pot but imo, I think you'd see diminishing return on really long 14/10 periods, like beyond 2 weeks. Cheers.
 
DangerDave

DangerDave

Member
All very interesting stuff. I've been doing speed transitions into flower from veg - 24 hours light 36 hours darkness then into 12/12. Anyone else messing around with this?
 
GroErr

GroErr

Well-Known Member
DangerDave said:
All very interesting stuff. I've been doing speed transitions into flower from veg - 24 hours light 36 hours darkness then into 12/12. Anyone else messing around with this?
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Interesting, is there a reason or theory or just doing some testing? I've heard of dark period prior to flowering but never tried it. What's stopped me trying that is I try to ease my plants into any transition, not shock them. Other than a dark period at the end of flowering but then the whole purpose of that IS to stress them into potentially throwing out more resin in response (still out on this one btw, not really seeing any significant difference imo).
 
DangerDave

DangerDave

Member
GroErr said:
Interesting, is there a reason or theory or just doing some testing? I've heard of dark period prior to flowering but never tried it. What's stopped me trying that is I try to ease my plants into any transition, not shock them. Other than a dark period at the end of flowering but then the whole purpose of that IS to stress them into potentially throwing out more resin in response (still out on this one btw, not really seeing any significant difference imo).
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My buddy does it and said I should give her a try. Not sure on reasoning besides the speedy transition..but yah I can agree on the darkness at end of flower. I've heard 24-48 hours I stick with 24
 
GroErr

GroErr

Well-Known Member
DangerDave said:
My buddy does it and said I should give her a try. Not sure on reasoning besides the speedy transition..but yah I can agree on the darkness at end of flower. I've heard 24-48 hours I stick with 24
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Ah, I see, I may try that with a strain where I know how it should transition and see what the outcome is, always looking for new methods, sometimes they work, sometimes they tank but worth a try. Funny thing is that most of my changes in methodology have come from accidents/observation rather than specifically trying new methods. The 14/10 thing was while I was finishing my flower room, my cabinet was full and I needed some work time with lights on so I ran the first 12 days @14/10 to get some additional time to work on the room. Another recent one was I needed some heat in a tent I run, so I threw in a DIY panel with a mix of 2700k CFL's and 4000k LED's for heat. Because it's a small tent and I had flowered a bit late, I ended up with the main light and this mixed spectrum panel of bulbs really close to the canopy, pretty well doubled my yield/density from a previous run in that tent. I think it was a combination of the spectrum mix and running them very close (8-10") from the canopy, trying another run now with the same setup to verify it. Go figure...
 
KLITE

KLITE

Well-Known Member
Interesting, never tried running them that long @14/10. Most I've gone I think was 12 days and that was the first time I did it, funny thing is that it was unintentional, my flower room needed some finishing touches to be ready and I decided to reduce them but not induce flowering, kind of a mistake really. Then I noticed the significant stretch (good as I tend to grow short/fat/dense bushes) and quick flowering time as soon as I flipped them to 12/12. Replicated that and have tried to use this method since then.

For my purpose, to get them pre-flowering/sexed and stretch them, 8-12 days works well and typically the main stretch period when flipping straight to 12/12. Having them @14/10 for 3-4 weeks would eventually begin flowering but I'd question the practice as imo it would increase total flowering time by a week or two. With 8-12 days @14/10 I've seen flowers pop up as soon as 3 days into 12/12. Not a huge difference between that and a straight flip into 12/12, could even speed things up but haven't tracked it closely enough to test that though. You'd have to try different lengths @14/10 with the same strain to find the sweet pot but imo, I think you'd see diminishing return on really long 14/10 periods, like beyond 2 weeks. Cheers.
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Although i see your point what he claimed could be true for different reasons. He claimed it could take a week longer to finish but that the yield is greatly improved. To be honest i see outdoor plants flowering when theyre getting 16 hours of light here in spain end of july. I think whatever hormone the plant needs to produce in order to pack flowers will be released with 10 hours of darkness no question. In nature the light period changes in flower triggering further production of that hormone when darkness period reaches 12h. I think making the transition from 6 to 12h of darkness more gradually would mimic nature slightly better by giving it that late summer light period for a few weeks inside until the plant finishes final stretch.
In my head it makes sense why the yield could be improved but im not sure i could explain it right, as if the plant gets to flower but gets 2 extra hours of light to get busy and use that extra energy to produce.
I suppose i just gotta give it a try... still skeptical though but it kind of makes sense in my head and i dont see why that guy would bollock me...
 
Cannasutraorganics

Cannasutraorganics

Well-Known Member
DangerDave said:
My buddy does it and said I should give her a try. Not sure on reasoning besides the speedy transition..but yah I can agree on the darkness at end of flower. I've heard 24-48 hours I stick with 24
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72 to 96. Strain dependant. And soak with cold water before starting. There is a whole procedure to do it right. It tightens buds and increases THC. Done and perfected two decades ago.
 
KLITE

KLITE

Well-Known Member
72 to 96. Strain dependant. And soak with cold water before starting. There is a whole procedure to do it right. It tightens buds and increases THC. Done and perfected two decades ago.
Click to expand...
I go 72 hours too. Last harvest under the microscope is jaw locking. Help get those few extra glands to amber too ime.
 
KLITE

KLITE

Well-Known Member
Well people Ive a room about 2 weeks in into a 14 hours period and its looking really good, i can tell stretch is nearly done though only beggining to show signs of sexing. Will decide end of the week whether it will go 21 days at 14 h or just about 14 days.
 
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