If I reduce daylight hours by 30 minutes per week from 18 hours, at what stage will plants show signs of flowering?

greengoblin2014

Well-Known Member
I have some unfeminised seeds that sprouted a few weeks ago. I'm currently on 18/6 light schedule.
My plan is to reduce the day light cycle by 30 minutes per week until I'm down from 18 hours to 13 hours, then I will put the plants outside mid spring where the outside daylight hours will also be at 13 hours of light. At some stage during this process are the plants going to go into flower and then have to wait for them to revert to veg? If the plants slightly go into flower this could be beneficial for me to then get rid of any males.
I'm just interested to know exactly when plants are likely to go into flower when reducing the light cycle in this way? TIA
 

VaSmile

Well-Known Member
I have some unfeminised seeds that sprouted a few weeks ago. I'm currently on 18/6 light schedule.
My plan is to reduce the day light cycle by 30 minutes per week until I'm down from 18 hours to 13 hours, then I will put the plants outside mid spring where the outside daylight hours will also be at 13 hours of light. At some stage during this process are the plants going to go into flower and then have to wait for them to revert to veg? If the plants slightly go into flower this could be beneficial for me to then get rid of any males.
I'm just interested to know exactly when plants are likely to go into flower when reducing the light cycle in this way? TIA
This is something that fasicnates me i feel is not discussed enough somewhere between 9 and 11 hours of darkness will trigger the bloom cycle not all strains are the same.

Your plants should show some sex traits after about 5 weeks of veg without flipping your lights no need to force flower and reveg.

If you do run this though please let us know the results. Testing for dark trigger times is something i have thought about doing
 

Billytheluther

Well-Known Member
This is something that fasicnates me i feel is not discussed enough somewhere between 9 and 11 hours of darkness will trigger the bloom cycle not all strains are the same.

Your plants should show some sex traits after about 5 weeks of veg without flipping your lights no need to force flower and reveg.

If you do run this though please let us know the results. Testing for dark trigger times is something i have thought about doing
Id like to see these results aswell.
Commenting on plants expressing sex once mature though, id like to state that ive had plants in veg for 6-7 weeks and still didn’t express sex..
pic i posted they were 59 days old, no sign of sex running them 17/7
 

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VaSmile

Well-Known Member
Id like to see these results aswell.
Testing for dark trigger times is something i have thought about doing
The bigest hesistestion is if this was really that big of a deal there would already be more information on it and it would be something breeders regulary test for. I can afford to take the time and space to veg for as long as ut takes. but its just a big investment of time to scream numbers in to the void searching for a few rare exceptions, my hypothises is the vast majority ar going to be about 9.75hr(+/-)15 mins
 

Billytheluther

Well-Known Member
The bigest hesistestion is if this was really that big of a deal there would already be more information on it and it would be something breeders regulary test for. I can afford to take the time and space to veg for as long as ut takes. but its just a big investment of time to scream numbers in to the void searching for a few rare exceptions, my hypothises is the vast majority ar going to be about 9.75hr(+/-)15 mins
This has been done in the past many times, people would bring down their cycle slowly trying to replicate nature.
Depending on strain type I believe growing occurs from 9-14 hours of light.
Theres even thinggs crazy like the old
14-4 for veg and 6-12 for flower with the idea being thats all thats required hence making for shorter “days” and speeding up growth in a shorter amount of time
 

VaSmile

Well-Known Member
This has been done in the past many times, people would bring down their cycle slowly trying to replicate nature.
Depending on strain type I believe growing occurs from 9-14 hours of light.
Theres even thinggs crazy like the old
14-4 for veg and 6-12 for flower with the idea being thats all thats required hence making for shorter “days” and speeding up growth in a shorter amount of time
In all my reserch i have not found anything that strain Z triggers at Xhrs dark time. Best i find is a harvest month which also accounts for lenth of bloom cycle and lattitude. Sometimes you get a warning not to put them out to early.

I know about gas latern in bloom to try and replicate the oncoming of winter and people tuning down their veg time to match daylight hrs when they go outside to prevent blooming. (Idk why they dont just veg on the time of they day they plan to put it out?)
As far as trying to hammer out a needed dark time to bloom info i just can't find. If you got sources please share

If i can Find strains that tigger at 9hrs or less then i can put some out early and they will bloom though the sostice and i know i can get 2 harvest a year maybe 3 if mother nature cooperates. If i can find strains that i know need 11hrs or more i can put them out early have a long veg season and harvest a monster in late october.
 

Billytheluther

Well-Known Member
In all my reserch i have not found anything that strain Z triggers at Xhrs dark time. Best i find is a harvest month which also accounts for lenth of bloom cycle and lattitude. Sometimes you get a warning not to put them out to early.

I know about gas latern in bloom to try and replicate the oncoming of winter and people tuning down their veg time to match daylight hrs when they go outside to prevent blooming. (Idk why they dont just veg on the time of they day they plan to put it out?)
As far as trying to hammer out a needed dark time to bloom info i just can't find. If you got sources please share

If i can Find strains that tigger at 9hrs or less then i can put some out early and they will bloom though the sostice and i know i can get 2 harvest a year maybe 3 if mother nature cooperates. If i can find strains that i know need 11hrs or more i can put them out early have a long veg season and harvest a monster in late october.
Sorry, my comment was referring to indoor light schedules, im sure you can do it outdoors with light deprivation but it would need a lot of automation if growing monsters..
Heres a screenshot from a different forum i looked up on the method, i dont know if i can mention the name so i just snapped a pic..
 

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VaSmile

Well-Known Member
Sorry, my comment was referring to indoor light schedules, im sure you can do it outdoors with light deprivation but it would need a lot of automation if growing monsters..
Heres a screenshot from a different forum i looked up on the method, i dont know if i can mention the name so i just snapped a pic..
To the bolden. The point is to elimenate the need to do so, or to maximize veg time.
Pulling tarp is for the birds.

Thanks for the write up. Ive seen many discussions on such things but never an account.
 
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amneziaHaze

Well-Known Member
14h or less light will cause it to bloom.depends on strain some will not at 14..... allsoo the plant has to be old enough usually anything over 23 days but again strain dependant
 

Red Hard Head

Well-Known Member
I have some unfeminised seeds that sprouted a few weeks ago. I'm currently on 18/6 light schedule.
My plan is to reduce the day light cycle by 30 minutes per week until I'm down from 18 hours to 13 hours, then I will put the plants outside mid spring where the outside daylight hours will also be at 13 hours of light. At some stage during this process are the plants going to go into flower and then have to wait for them to revert to veg? If the plants slightly go into flower this could be beneficial for me to then get rid of any males.
I'm just interested to know exactly when plants are likely to go into flower when reducing the light cycle in this way? TIA
In my experience most strains that are hybrids with. Indica need 14+ hours light to maintain veg.
I put my seedlings out in early April to harden off and sex. Its rare for seedlings to declare their sex in veg. Females are easier to spot in this circumstance.
Pure sativas can handle 13 hours light and veg just fine. Good for light dep not so much full term in northern states or canadastan.
Indoor runs, I just sex them at around 2 months by 12/12 for a few days then back to 14/10.
Keep a few extra if growing outdoors. May or june cool weather will trigger many strains to flower even with 14+ hours light. Sometimes you have to replant.

The biggest factor to flowering is a dimer protein, phytochromeR / phytochrome FR. It controls the flowering by registering the amount of red and far red light. At dusk there is more red and far red light that triggers a change to the protein to a structure that promotes shortened nodes and flower development. Its changed into a structure that promotes longer nodes and veg growth during the day. During long days, more veg version of phytochrome dominates growth. As days shorten the flowering version of phytochrome becomes more dominant.

I tried making a n outdoor red/ far red light, to trigger flowering during summer without pulling tarps. By triggering the plant with red/ far red in morning and evening in theory it should stimulate flowering. This has been done with other crops as well as indoor cannabis. I proved concept but not reliable for large grows more due to variability in wavelength and intensity of each bulb. Red/far red needs high intensity of a specific wavelength range, thats pretty narrow to begin with. Its not an off the shelf project.
 

VaSmile

Well-Known Member
Once again

Sorry again, i didnt realize the original question was to maximize veg time..
I think op wants to eleminate males. He thinks forcing them to bloom and revegging is a way to go, in which case there is no need for the tappering down just turn lights to 12/12. I would recomend not doing that, cutting clones to bloom the eliminating any corrosponding fathers. Reveg is stressful on plant and takes a bit of time
 

VaSmile

Well-Known Member
In my experience most strains that are hybrids with. Indica need 14+ hours light to maintain veg.
Pure sativas can handle 13 hours light and veg just fine. Good for light dep not so much full term in northern states or canadastan.
For the indicas, at solstice my light cycle is 14:50/9:10 so to confidently pull off a spring bloom and second crop, i need to find the extremophiles that will stay in bloom closer to 15/9 then to 14/10.
Fot the sativas 13/11 is hit april 10th and september 1st i dont think it would be an issue to harvest around halloween but idk of many 9 week tivas (cindy 99?) Id say pushing to thanksgiving would work about 1in5 season
 

Red Hard Head

Well-Known Member
Good luck keeping cannabis in bloom with 15/9. Or any time around the solstice. The spectrum is heavily blue green with long days. You would likely need some ruderalis in the genetics. Auto flowers.
There are some strains that will start flowering or finish at 14:30 hrs light. I ran Bodhi's OG Lion seeds some years ago that I could only put out after veg on 16/8 in June. By by 1st week of September done. Fantastic smoke.
Some hindu kush high elevation strains will start flowering in July (Nepalese or tibetan some paki or ghani. OG Lion was Nepalese?). They are more a high elevation sativa really. Let me say the yeild may be medium but the potency and gassy petrol terps unrivaled. Its a unique type of high. Superior.
Those could get you 3 harvests a season.
Short season crack seeds in feb or March harvest mid late may.
Long season crack seeds in late march or early April, sex, plant ladies finish when they are done.
Long-short season crack seeds in June finished when done. Sometimes quicker than long season. This is when I test to see if worth going big plant long season.
All strains Ive ever grown reveg hard from the 2nd week of June to 2nd week of July. Even Auto flowers have a stretch during this time affecting bud structure though not potency ( grown literally shit tons of commercial auto flower hemp. Three crops from may thru September). From the Hawaiian tropics, southern mainland US, great lakes region or PNW didn't matter unless you can dep.
Believe me I tried many tricks and strains cause my birthday is end of June and hard to harvest fresh bud for my birthday. Nepalese rocket and OG Lion etc were the only ones that I could let finish and harvest a week before my birthday as short season plants in June. Anything else going past may 25th would reveg single leaf indeterminate flower/ veg growth.
 

greengoblin2014

Well-Known Member
Thanks everyone for the amazing replies.
My strains do contain Indica so knowing they will likely go into flower with anything below 14 hours is good to know.
I'm based in NZ, it's winter now. My plan is to mainline the plants from seed over winter get them pruned to 8-16 tops (maybe more) and put them outside mid spring already mature and pruned.
Currently I don't know the sex, my new plan is to take cuttings from each plant and then use the cuttings under 12/12 to find sex, this way I can save time and money with soil and pots etc.
After I've figured out sex I want to work out when is the best date to put them outside so they don't go under 14 hours and go to flower and also reduce lights gradually each week until I'm matching the 14 hours outside.
 

greengoblin2014

Well-Known Member
Actually just been checking through the NZ weather, they should be ok to go out beginning of November. If I have to put them out a bit early in October then it's ok if they go into flower a little and then revert back to veg but I can do my best to try and prevent that.
 
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