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going from 20 hrs light to 15ish

  • Thread starter Thread starter imgrowing
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going from 20 hrs light to 15ish

imgrowing 84 Replies 8,259 Views
Page 2 of 5 · Replies 21–40 of 85
#21
imgrowing said:
ok all good, but explain to me how people at latitude 48 can possibly grow photos outside then?
here it would take until december to have 14 hrs light or less for 10+ weeks for the girls to ripen.
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Auto strains where created in those conditions soooo
 
#22
imgrowing said:
what i'm trying is forced flowering when going from 20 hrs to 16 and diminishing from there.
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imgrowing said:
why do i get the feeling that everybody here wants this experiment to fail?
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HerbalEdu said:
you can't just stab in the dark with lenght of daylight and hoping that work
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well in fact you can slowly decrease from 16hours but not all phenos may start flowering at the same time.

you'll save you lot of time, understanding the science behind flowering photoperiods. nothing new about your experiment ... this has been done long time ago ...
 
#23
imgrowing said:
turned the timer up to 20 hrs light for photos. how long should i leave them inside before i put them outside to start flowering?
current sunlight hrs are 14 hrs 50 min here and getting longer until june 21 which will be 16 hrs sunlight.
1st time doing photos outside so i have no clue, southern vancouver island.
i want them to start the transition to flower asap once outside
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matter is less to make them transition to flower than keeping into flower once outdoor and not revegging because not enough nightime and uninterrupted darkness, photoperiods can revert from flowering to vegetation.

that's why you need to use light deprivation technique if put too early in flower outdoor from indoor so they won't reveg.
 
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#24
No one is trying to be a dick. No one is hoping your grow fails. What people are pointing out is the physiology of short day plants. They are genetically programmed to flower at a specific darkness intervals ... meaning 10 hrs or more of darkness. This is universal with photo-period cannabis plants. The change from 20 hrs of light to 16 hrs of light is usually not enough on its own to trigger flowering because 16 hrs of light in nature is still a long day light cycle.

Yes, its a 4 hr drop in the amount of light it receives. No, its not going to be enough to trigger flowering because of the genetic make-up of the plant. The only exception would be plants that have been bred for either "fast flower" ... which moves the goalpost for flowering to about 9.5 hrs of darkness or "auto-flowers."

I told you a couple of weeks ago that your only sure-fire way to ensure a harvest is to grow auto-flower plants on Vancouver Island. You still have time but in a few more weeks, that time will be behind you. Now, once again, no one is trying to be a dick or "wants" you to fail .... what you're trying to do with your argument is to re-invent the way nature has made cannabis to flower. This is beyond your control no matter what you do or how hard you try .... short of light deprivation techniques to get your plants flowering.

Your experiment is paramount to saying "If I try hard enough and drop enough rocks, maybe one will defy gravity and float instead of fall to the ground." This is why you sense people giving off a negative vibe to your posts. They know that cannabis doesn't work they way you want it to and your experiment will end in disappointment.

Or you can take my advice and grow some auto-flowers and have a nice bountiful harvest by September.
 
#25
photoperiod plants, including most cannabis strains, transition to flowering when sunlight hours start decreasing. This is because they are sensitive to changes in the ratio of daylight to darkness and use it as a cue to shift from vegetative growth to flowering for reproduction.



Explanation:
  • Photoperiodism:
    This is the process where plants use light as a cue to regulate their growth and development, including flowering.
  • Short-day plants:
    Most cannabis strains are short-day plants, meaning they flower when the days grow shorter and the nights grow longer.



  • Natural cues:
    In their natural environment, this typically happens after the summer solstice when daylight starts decreasing.

  • this was copy and paste
  • so why am i so wrong?
  • everything i read says this.
  • and yes i know all about autos
 
#26
imgrowing said:
photoperiod plants, including most cannabis strains, transition to flowering when sunlight hours start decreasing. This is because they are sensitive to changes in the ratio of daylight to darkness and use it as a cue to shift from vegetative growth to flowering for reproduction.



Explanation:
  • Photoperiodism:
    This is the process where plants use light as a cue to regulate their growth and development, including flowering.

  • Short-day plants:
    Most cannabis strains are short-day plants, meaning they flower when the days grow shorter and the nights grow longer.




  • Natural cues:
    In their natural environment, this typically happens after the summer solstice when daylight starts decreasing.

  • this was copy and paste
  • so why am i so wrong?
  • everything i read says this.
  • and yes i know all about autos
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Because even 15 hours of daylight is still considered "long day." Short day means 14 hrs or less of light when it comes to cannabis. Better stated would be a minimum of 10 hours of darkness without any kind of light leaks.

Edit: Are they still in containers? If they are and you want them to flower, put them in a dark shed every night exactly at 6pm. Remove them every morning at exactly 6am and put them in the sunlight. Do this starting June 22nd and by August 22nd you'll have been in flower for 8 weeks. From there, you should be close to the finish line. This would be how you would get photos to finish on Vancouver Island.

As for knowing "ALL" about autos ... I doubt it. Otherwise you would be growing them. They can be hard hitting and long lasting thanks to modern breeder improvements.
 
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#27
RoadKillSkunkHunt said:
Because even 15 hours of daylight is still considered "long day." Short day means 14 hrs or less of light when it comes to cannabis. Better stated would be a minimum of 10 hours of darkness without any kind of light leaks.
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small light leaks has been proven wrong many times, is a full moon not considered light?
and again nobody has bred plants to grow here but yet lots of people grow photos outside, and we don't get 10 hrs darkness until october 30.
the issue here is when the rain hits and that's usually late sept early oct.
and most, not all, girls are done by then.
not trying to imply the i'm right your wrong attitude at all.
to late to change anything now anyways.
wish me luck.
lol
 
#29
RoadKillSkunkHunt said:
Edit: Are they still in containers? If they are and you want them to flower, put them in a dark shed every night exactly at 6pm. Remove them every morning at exactly 6am and put them in the sunlight. Do this starting June 22nd and by August 22nd you'll have been in flower for 8 weeks. From there, you should be close to the finish line. This would be how you would get photos to finish on Vancouver Island.
Click to expand...

Read the edit above:

Here it is again:

Are they still in containers? If they are and you want them to flower, put them in a dark shed every night exactly at 6pm. Remove them every morning at exactly 6am and put them in the sunlight. Do this starting June 22nd and by August 22nd you'll have been in flower for 8 weeks. From there, you should be close to the finish line. This would be how you would get photos to finish on Vancouver Island.
 
#31
RoadKillSkunkHunt said:
Read the edit above:

Here it is again:

Are they still in containers? If they are and you want them to flower, put them in a dark shed every night exactly at 6pm. Remove them every morning at exactly 6am and put them in the sunlight. Do this starting June 22nd and by August 22nd you'll have been in flower for 8 weeks. From there, you should be close to the finish line. This would be how you would get photos to finish on Vancouver Island.
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kind of hard to do that in 20 gallon pots.
but yes, i know what your saying
 
#32
imgrowing said:
kind of hard to do that in 20 gallon pots.
but yes, i know what your saying
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Do you have a wagon or a wheel barrow? Maybe a garden tractor and a small trailer? If you plan now, you can execute this and have nice buds harvested by the start of the wet fall weather.
 
#33
imgrowing said:
small light leaks has been proven wrong many times, is a full moon not considered light?
and again nobody has bred plants to grow here but yet lots of people grow photos outside, and we don't get 10 hrs darkness until october 30.
the issue here is when the rain hits and that's usually late sept early oct.
and most, not all, girls are done by then.
not trying to imply the i'm right your wrong attitude at all.
to late to change anything now anyways.
wish me luck.
lol
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@imgrowing

When it comes to light, rule of thumb is if you can read 11 pt text like is typically found in books, there's too much light. The moon is a long ways away. It may seem bright but it's not of the intensity to allow you to read. However, street lights and porch lights are well known to cause erratic flowering in cannabis plants. It may not seem as bright as the moon, but its in closer proximity so yes, that light would be enough to disturb the darkness cycle. So no, I don't buy into your statement that "small light leaks" have been proven wrong many times. In my experience, small light leaks lead to hermaphroditism in some cannabis strains.

Here's what Google's chat AI has to say about cannabis plants flowering at 15 hours of light (9 hours of darkness).

Question: Are you aware of any photoperiod cannabis plants that begin flowering at 9 hours of darkness

Most photoperiod cannabis plants are classified as "short-day plants," meaning they initiate flowering when the period of uninterrupted darkness exceeds a certain critical length. For the vast majority of commonly cultivated photoperiod cannabis strains, this critical dark period is typically around 10 to 12 hours.
  • The industry standard for inducing flowering indoors is a 12 hours of light / 12 hours of uninterrupted darkness (12/12) schedule. This is a reliable trigger for almost all photoperiod strains.
While some studies and anecdotal reports suggest that certain cultivars might begin to show signs of flowering with slightly shorter dark periods, 9 hours of darkness (meaning 15 hours of light) is generally considered to be insufficient to reliably induce flowering in most photoperiod cannabis plants. In fact, a 15/9 light cycle is often used to maintain plants in a vegetative state, as anything less than 10 hours of darkness can prevent flowering.
However, there are nuances:
  • Critical Dark Period Variation: Some studies on various cannabis genotypes (including hemp varieties) have shown differences in their critical photoperiod requirements. Some might flower with slightly less than 12 hours of darkness (e.g., 10.5 or 11 hours), but 9 hours is pushing the very extreme edge of what's typically observed for inducing flowering.
  • "Fast Flowering" or "F1 Fast Version" Strains: Seed banks offer "fast flowering" or "F1 Fast Version" photoperiod strains. These are typically F1 hybrids created by crossing a photoperiod strain with an autoflowering strain. While still photoperiod-dependent, they have a shorter overall flowering time once induced (e.g., 6-7 weeks instead of 8-10+). However, they still require a long enough dark period (usually 12+ hours of darkness) to initiateflowering. Their "fast" nature refers to the duration of the bloom cycle, not the darkness requirement to trigger it.
  • Environmental Factors: Other factors like temperature, stress, and plant maturity can subtly influence a plant's sensitivity to photoperiod changes, but they generally won't override the fundamental requirement for a sufficient dark period.
In summary:
It's highly unlikely you will find a reliable photoperiod cannabis plant that consistently initiates flowering with only 9 hours of darkness. The standard and most reliable trigger is 12 hours of uninterrupted darkness. If a plant were to show signs of flowering under 9 hours of darkness, it would be an extreme outlier or potentially exhibiting characteristics of autoflowering genetics.
If you are looking for plants that flower under longer light periods, you should consider autoflowering strains, which initiate flowering based on age rather than light cycles and can be grown under 18/6 or even 20/4 light cycles throughout their life.
 
#34
RoadKillSkunkHunt said:
Do you have a wagon or a wheel barrow? Maybe a garden tractor and a small trailer? If you plan now, you can execute this and have nice buds harvested by the start of the wet fall weather.
Click to expand...
i'm 62 with a completely destroyed back, the girls stay where they are.
worst case is they flower and re-veg, then lesson learned.
nobody succeeds without trying otherwise we'd all be living by the campfire.
i still have a shed full of autos going so no loss.
and there was 1 person here that thought this might work
 
#35
RoadKillSkunkHunt said:
@imgrowing

When it comes to light, rule of thumb is if you can read 11 pt text like is typically found in books, there's too much light. The moon is a long ways away. It may seem bright but it's not of the intensity to allow you to read. However, street lights and porch lights are well known to cause erratic flowering in cannabis plants. It may not seem as bright as the moon, but its in closer proximity so yes, that light would be enough to disturb the darkness cycle. So no, I don't buy into your statement that "small light leaks" have been proven wrong many times. In my experience, small light leaks lead to hermaphroditism in some cannabis strains.

Here's what Google's chat AI has to say about cannabis plants flowering at 15 hours of light (9 hours of darkness).

Question: Are you aware of any photoperiod cannabis plants that begin flowering at 9 hours of darkness

Most photoperiod cannabis plants are classified as "short-day plants," meaning they initiate flowering when the period of uninterrupted darkness exceeds a certain critical length. For the vast majority of commonly cultivated photoperiod cannabis strains, this critical dark period is typically around 10 to 12 hours.
  • The industry standard for inducing flowering indoors is a 12 hours of light / 12 hours of uninterrupted darkness (12/12) schedule. This is a reliable trigger for almost all photoperiod strains.
While some studies and anecdotal reports suggest that certain cultivars might begin to show signs of flowering with slightly shorter dark periods, 9 hours of darkness (meaning 15 hours of light) is generally considered to be insufficient to reliably induce flowering in most photoperiod cannabis plants. In fact, a 15/9 light cycle is often used to maintain plants in a vegetative state, as anything less than 10 hours of darkness can prevent flowering.
However, there are nuances:
  • Critical Dark Period Variation: Some studies on various cannabis genotypes (including hemp varieties) have shown differences in their critical photoperiod requirements. Some might flower with slightly less than 12 hours of darkness (e.g., 10.5 or 11 hours), but 9 hours is pushing the very extreme edge of what's typically observed for inducing flowering.
  • "Fast Flowering" or "F1 Fast Version" Strains: Seed banks offer "fast flowering" or "F1 Fast Version" photoperiod strains. These are typically F1 hybrids created by crossing a photoperiod strain with an autoflowering strain. While still photoperiod-dependent, they have a shorter overall flowering time once induced (e.g., 6-7 weeks instead of 8-10+). However, they still require a long enough dark period (usually 12+ hours of darkness) to initiateflowering. Their "fast" nature refers to the duration of the bloom cycle, not the darkness requirement to trigger it.
  • Environmental Factors: Other factors like temperature, stress, and plant maturity can subtly influence a plant's sensitivity to photoperiod changes, but they generally won't override the fundamental requirement for a sufficient dark period.
In summary:
It's highly unlikely you will find a reliable photoperiod cannabis plant that consistently initiates flowering with only 9 hours of darkness. The standard and most reliable trigger is 12 hours of uninterrupted darkness. If a plant were to show signs of flowering under 9 hours of darkness, it would be an extreme outlier or potentially exhibiting characteristics of autoflowering genetics.
If you are looking for plants that flower under longer light periods, you should consider autoflowering strains, which initiate flowering based on age rather than light cycles and can be grown under 18/6 or even 20/4 light cycles throughout their life.
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google AI?
lol
 
#37
imgrowing said:
google AI?
lol
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Best of luck to you. I've explained how this works. I've explained your options. I even told you what you should do before you moved them outside to 20 gallon bags. On top of that, there were many other people stating you're barking up the wrong tree. Your photo-period plant experiment isn't new. It's been done many times before with disappointing results.

At least you have the auto-flowers. You will have cannabis with those.

imgrowing said:
Bruce Bugbee is the Director of the Crop Physiology Laboratory at Utah State University in their Plants, Soils & Climate Department.
they grow cannabis there so i'll listen to him instead of a fancy wiki thanks
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Show me where Dr Bruce Bugbee says you can do what you're trying to do? No where in any of his lectures will he tell you that you can flower a short day cannabis under a long day light cycle.

Again, best of luck.
 
#38
RoadKillSkunkHunt said:
Best of luck to you. I've explained how this works. I've explained your options. I even told you what you should do before you moved them outside to 20 gallon bags. On top of that, there were many other people stating you're barking up the wrong tree. Your photo-period plant experiment isn't new. It's been done many times before with disappointing results.

At least you have the auto-flowers. You will have cannabis with those.



Show me where Dr Bruce Bugbee says you can do what you're trying to do? No where in any of his lectures will he tell you that you can flower a short day cannabis under a long day light cycle.

Again, best of luck.
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RoadKillSkunkHunt said:
Best of luck to you. I've explained how this works. I've explained your options. I even told you what you should do before you moved them outside to 20 gallon bags. On top of that, there were many other people stating you're barking up the wrong tree. Your photo-period plant experiment isn't new. It's been done many times before with disappointing results.

At least you have the auto-flowers. You will have cannabis with those.



Show me where Dr Bruce Bugbee says you can do what you're trying to do? No where in any of his lectures will he tell you that you can flower a short day cannabis under a long day light cycle.

Again, best of luck.
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my response was more about light leaks than hrs of light
 
#40
imgrowing said:
my response was more about light leaks than hrs of light
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and their my girls anyways so what's with every one's negative attitude?
RoadKillSkunkHunt said:
And as I already told you, light leaks are a leading cause of hermaphroditism in cannabis.
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herming can also be attributed to genetics as some of these crosses are prone to that. just like some are prone to mould etc.
am i wrong on that as well?
maybe you grow land races but i don't have the climate outdoors to doo it
 
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