Daylength and the appearance of first flowers - Cannabis Growing Outdoors - International Cannagraphic Magazine Forums

07-16-2008, 06:31 AM

I wanted to pass on the results of a little experiment that I have just completed as others might be interested in the info.

I wanted to know how many days it took from the time my plants were exposed to 13.5 hrs of daylight before I began to see the first flowers and then, the first buds. I chose the daylength of 13.5, because thats the daylenght I assumed I had at 38 degrees on Aug. 1, which is the date I normally see flowers. Ive seen this in several daylength charts for my lat.

First let me say that all 4 of the plants in my experiment are mostly indica, over 80%. 3 cream caramel from sweetseeds and 1 Sadhu from Mandala.

On July 3, I began setting my plants in the grow shed for a period that resulted in 13.5 hrs of daylength . On that date, the plants were fully in the veg stage. The first visible changes in the plants came 4 days later, when the small shoots in the branches began to thicken and change color to purple. The first real flower appearance was on the 11th, 7 full days after I began the dark treatment. The first real bud appearance occurred during the day of the 14th of july, eleven days after the 13.5 treatments began.( I have some pictures showing these flowers but cant upload, ill continue to try)

My conclusions after this rough experiment were that it took about a week after 13.5 was reached to see the first flowers and 11 days or more before small buds were observed.

Shorty after believing I had leaned something, I made a discovery that threw my 13.5 hr belief into chaos. At my lattitude, 38, first flowers for indica strains are seen by Aug 1 generally. Given that my results would indicate that it takes about a week for flowers to appear after appropriate light levels are seen, logic would suggest that here at this lat, the trigger date for flowering is approximately July 23, or 7 days before 8/1.

Today is the 16th of July, and according to sunrise/sunset as listed in the daily paper, sunrise is 6:29 and sunset is 8:59, which is 14.5 hrs. It appears from following the sunrise/sunset times for a week that I am loosing around 3 minutes of daylength per day, indicating that a week from now, I will be at about 14 hrs and 7 minutes of daylength, which I can only conclude that this is the daylength that at my lattitude, will trigger flowering. 14 hrs and 7 minutes sound like a long daylength to me.

My real problem with this number is that i disagree with the papers assessment of when sunrise/sunset begins. I would add at least another 30 minutes to their length because the level of brightness at 6:15 am is significant, as it is at 9:15pm. This would mean in real terms that my indica plants are really being kicked into flower around july 23rd at about 14.45 minutes of daylength, and that is very puzzling to me. Isnt that extremely high? (yes, i was too during most of this experiment)

Anybody have any thoughts or input regauding these astounding findings and conclusions?

Rob547 · 07-16-2008, 07:45 AM

Huh, interesting idea for an experiment. Being a first timer outdoors I've been wondering the same thing for the past month or so. Im a little more North, about 42 degrees. According to one of the stickies about daylight periods, I have about 2 weeks till 14.5 and a month or so till under 14 hours of light. Personally I didn't think they would start flowering at all until 14 hours. I agree with you though about the amount of light at sunrise/set. My plants get direct sun from maybe 7:30am? to about 5:30, but its pretty light when I get up at 6:30 and it stays bright till at least 9. But it lists sunset @ 8:20. I know this isn't very helpful, just my 2 cents. I'll definitely keep track of when flowering/budding starts though.

BigWillyDee · 07-16-2008, 07:47 AM

i'm at 35 degrees and all of my white label northern lights have started to flower... BUT it has been raining for the past week and a half so................

BELOW FRIGID · 07-16-2008, 07:51 AM

I am just north of the 36 line and some males are already growing balls? I also Have one girl that has been flowering for a few weeks now? I guess it is what you call an auto flower. Should I be worried about a plant like this going hermie on me? I am wondering if all the smoke has anything with flowering early.

chubbynugs · 07-16-2008, 08:09 AM

Yeah man dont forget about twilight. Before sunrise and after sundown there is still light hitting your plants.

07-16-2008, 09:01 AM

Hi everyone.
I guess the biggest suprise for me was the amount of daylight at the time the plants must be triggering to flower which appears to be about 14.5 around July 23. I always new that most indica strains would trigger by 14, but not 14.5. I had never looked in the paper to see their designations of sunrise/sunset.

Rob547, check the daylength at when you first see flowers and let us know.

BigWillieDee, Ive grown NL several times from different banks and every time it has started to flower before the end of July at 38. I don't know your experience but I consider NL one of the earliest hybrids available. I don't think thats widely known. Look in the paper and tell us what it says your daylength currently is and if its really light and dark at those times. Here, at 6:29, you don't need headlights at all.

BF, generally males flower before females so thats not unusual. The females should start in the next couple of weeks. Its certainly no indication of hermaphroditism, so don't worry about that. The one thats been flowering a few weeks probably is an auto. I don't know of anystrain that would be in full flower at the first of july that isn't.

And a lot of it chubbynugs. I was being very generous when I only added 15 minutes to the papers sunrise/sunset time, but in reality, its daylight here in my mind by 6:05, not 6:29.

NickMode · 07-16-2008, 09:15 AM

im at 39n and i havent bee to my plot in 10 days. About to go out no and check it out. Ill be back with updates

BELOW FRIGID · 07-16-2008, 09:39 AM

Quote:

Originally Posted by silverback

Hi everyone.
I guess the biggest suprise for me was the amount of daylight at the time the plants must be triggering to flower which appears to be about 14.5 around July 23. I always new that most indica strains would trigger by 14, but not 14.5. I had never looked in the paper to see their designations of sunrise/sunset.

Rob547, check the daylength at when you first see flowers and let us know.

BigWillieDee, Ive grown NL several times from different banks and every time it has started to flower before the end of July at 38. I don't know your experience but I consider NL one of the earliest hybrids available. I don't think thats widely known. Look in the paper and tell us what it says your daylength currently is and if its really light and dark at those times. Here, at 6:29, you don't need headlights at all.

BF, generally males flower before females so thats not unusual. The females should start in the next couple of weeks. Its certainly no indication of hermaphroditism, so don't worry about that. The one thats been flowering a few weeks probably is an auto. I don't know of anystrain that would be in full flower at the first of july that isn't.

And a lot of it chubbynugs. I was being very generous when I only added 15 minutes to the papers sunrise/sunset time, but in reality, its daylight here in my mind by 6:05, not 6:29.

The auto fower is the only one that confuses me. Yeah I know the males always show first, LOL. It just seems that some are way early this year. I did have one female herm on me last year. I am going to keep a close eye on that autoflowering girl.

BigWillyDee · 07-16-2008, 11:26 AM

well the paper has it as 5:27 & 7:44 however like everyone else it is usually light enough to see from maybe 5 till 9-9:30 so.....i think the early tendency of the strain with all the rain just pushed me forward a little...

i checked another area today with some freebie seeds thai haze x skunk and nothing has shown yet.

07-16-2008, 11:31 AM

Hey NickMode, we'll be waitin

You know BF, it seems like i hardly ever grow a strain, any strain, that I dont find a seed or 2 during the winter when its being smoked, and you can tell it was a male flower on the plant and not some drifing pollen because all the seeds will be in one or 2 buds and not others.Its impossible in my view to find a male flower on a big plant in the field. In fact, I find fewer seeds in the femminized strains I grow than i do in the standard strains. Female cannabis plants often produce a male flower or 2 and I dont think theres much you can do about it.
That's different of course than having one with manberries all over it.

07-16-2008, 06:31 AM	#1
Guest Guest Posts: n/a	Daylength and the appearance of first flowers I wanted to pass on the results of a little experiment that I have just completed as others might be interested in the info. I wanted to know how many days it took from the time my plants were exposed to 13.5 hrs of daylight before I began to see the first flowers and then, the first buds. I chose the daylength of 13.5, because thats the daylenght I assumed I had at 38 degrees on Aug. 1, which is the date I normally see flowers. Ive seen this in several daylength charts for my lat. First let me say that all 4 of the plants in my experiment are mostly indica, over 80%. 3 cream caramel from sweetseeds and 1 Sadhu from Mandala. On July 3, I began setting my plants in the grow shed for a period that resulted in 13.5 hrs of daylength . On that date, the plants were fully in the veg stage. The first visible changes in the plants came 4 days later, when the small shoots in the branches began to thicken and change color to purple. The first real flower appearance was on the 11th, 7 full days after I began the dark treatment. The first real bud appearance occurred during the day of the 14th of july, eleven days after the 13.5 treatments began.( I have some pictures showing these flowers but cant upload, ill continue to try) My conclusions after this rough experiment were that it took about a week after 13.5 was reached to see the first flowers and 11 days or more before small buds were observed. Shorty after believing I had leaned something, I made a discovery that threw my 13.5 hr belief into chaos. At my lattitude, 38, first flowers for indica strains are seen by Aug 1 generally. Given that my results would indicate that it takes about a week for flowers to appear after appropriate light levels are seen, logic would suggest that here at this lat, the trigger date for flowering is approximately July 23, or 7 days before 8/1. Today is the 16th of July, and according to sunrise/sunset as listed in the daily paper, sunrise is 6:29 and sunset is 8:59, which is 14.5 hrs. It appears from following the sunrise/sunset times for a week that I am loosing around 3 minutes of daylength per day, indicating that a week from now, I will be at about 14 hrs and 7 minutes of daylength, which I can only conclude that this is the daylength that at my lattitude, will trigger flowering. 14 hrs and 7 minutes sound like a long daylength to me. My real problem with this number is that i disagree with the papers assessment of when sunrise/sunset begins. I would add at least another 30 minutes to their length because the level of brightness at 6:15 am is significant, as it is at 9:15pm. This would mean in real terms that my indica plants are really being kicked into flower around july 23rd at about 14.45 minutes of daylength, and that is very puzzling to me. Isnt that extremely high? (yes, i was too during most of this experiment) Anybody have any thoughts or input regauding these astounding findings and conclusions? Last edited by silverback; 07-16-2008 at 06:45 AM..
	Quote

07-16-2008, 07:45 AM	#2
Rob547 East Coast Grower Join Date: Jul 2007 Location: Northeast Posts: 1,099	Huh, interesting idea for an experiment. Being a first timer outdoors I've been wondering the same thing for the past month or so. Im a little more North, about 42 degrees. According to one of the stickies about daylight periods, I have about 2 weeks till 14.5 and a month or so till under 14 hours of light. Personally I didn't think they would start flowering at all until 14 hours. I agree with you though about the amount of light at sunrise/set. My plants get direct sun from maybe 7:30am? to about 5:30, but its pretty light when I get up at 6:30 and it stays bright till at least 9. But it lists sunset @ 8:20. I know this isn't very helpful, just my 2 cents. I'll definitely keep track of when flowering/budding starts though. __________________ Past OD: https://www.icmag.com/ic/showthread.php?t=219225 https://www.icmag.com/ic/showthread....52#post1738552
	Quote

07-16-2008, 07:47 AM	#3
BigWillyDee Member Join Date: Mar 2008 Location: mexico Posts: 341	i'm at 35 degrees and all of my white label northern lights have started to flower... BUT it has been raining for the past week and a half so................
	Quote

07-16-2008, 07:51 AM	#4
BELOW FRIGID Banned Join Date: Feb 2007 Posts: 203	I am just north of the 36 line and some males are already growing balls? I also Have one girl that has been flowering for a few weeks now? I guess it is what you call an auto flower. Should I be worried about a plant like this going hermie on me? I am wondering if all the smoke has anything with flowering early.
	Quote

07-16-2008, 08:09 AM	#5
chubbynugs Registered Pothead Join Date: Jun 2007 Location: In the weed jungles of SoCal Posts: 2,895	Yeah man dont forget about twilight. Before sunrise and after sundown there is still light hitting your plants.
	Quote

07-16-2008, 09:01 AM	#6
Guest Guest Posts: n/a	Hi everyone. I guess the biggest suprise for me was the amount of daylight at the time the plants must be triggering to flower which appears to be about 14.5 around July 23. I always new that most indica strains would trigger by 14, but not 14.5. I had never looked in the paper to see their designations of sunrise/sunset. Rob547, check the daylength at when you first see flowers and let us know. BigWillieDee, Ive grown NL several times from different banks and every time it has started to flower before the end of July at 38. I don't know your experience but I consider NL one of the earliest hybrids available. I don't think thats widely known. Look in the paper and tell us what it says your daylength currently is and if its really light and dark at those times. Here, at 6:29, you don't need headlights at all. BF, generally males flower before females so thats not unusual. The females should start in the next couple of weeks. Its certainly no indication of hermaphroditism, so don't worry about that. The one thats been flowering a few weeks probably is an auto. I don't know of anystrain that would be in full flower at the first of july that isn't. And a lot of it chubbynugs. I was being very generous when I only added 15 minutes to the papers sunrise/sunset time, but in reality, its daylight here in my mind by 6:05, not 6:29.
	Quote

07-16-2008, 09:15 AM	#7
NickMode Nature fanatic. Join Date: Mar 2008 Posts: 558	im at 39n and i havent bee to my plot in 10 days. About to go out no and check it out. Ill be back with updates
	Quote

07-16-2008, 11:26 AM	#9
BigWillyDee Member Join Date: Mar 2008 Location: mexico Posts: 341	well the paper has it as 5:27 & 7:44 however like everyone else it is usually light enough to see from maybe 5 till 9-9:30 so.....i think the early tendency of the strain with all the rain just pushed me forward a little... i checked another area today with some freebie seeds thai haze x skunk and nothing has shown yet.
	Quote

07-16-2008, 11:31 AM	#10
Guest Guest Posts: n/a	Hey NickMode, we'll be waitin You know BF, it seems like i hardly ever grow a strain, any strain, that I dont find a seed or 2 during the winter when its being smoked, and you can tell it was a male flower on the plant and not some drifing pollen because all the seeds will be in one or 2 buds and not others.Its impossible in my view to find a male flower on a big plant in the field. In fact, I find fewer seeds in the femminized strains I grow than i do in the standard strains. Female cannabis plants often produce a male flower or 2 and I dont think theres much you can do about it. That's different of course than having one with manberries all over it.
	Quote