Cannabis Plants Will Flower Under 14 Hours Light

Cpappa27

Well-Known Member
So let me start by telling you how these plants started. These plants in this current grow sprouted at different times, as I had some issues with some not sprouting so added more, then some took forever to sprout, and some grew super slow etc so they are kinda different ages but all were sprouted within 2 weeks of each other. Most of them are the same age, such as the Skunk 1 x NL2 by AGseeds, and many of my own crossed with GDP. I know my GDP Photo x Auto crosses some of those will flower for obvious reasons. All the Skunk 1 x NL2 and a couple of the Sensi Skunk1 are full on flowering.

These were planted on September 25th. They were supposed to go in the tent as usual after a couple three weeks, after the grow at the time finished. Well that grow, my last one, took forever. They were supposed to be 8 week strains and turned out to be 13 weekers. So all those plants that I started I had to slow them down cause I didnt have the space for them to veg for 5 more weeks. I kept them in small 4x4 square pots and solo cups half full of dirt, and watered them daily or even twice daily, under a 90 watt LED under 16/8. I managed to keep them small by keeping them in those little pots, plus I didn't stop the fungus gnats, so they slowed them down a bit too.

On September 13th I had transplanted them into their tall 5 gallon fabric pots in my supersoil and put them into the tent under 16/8. They were pretty tall and stretchy but sturdy and strong. Around September 20th I reduced the light to 15/9. About week ago I reduced the light to 14/10. Now a week later there are full on bud sets, they are stretching, the males are full on flowering. The sensi isnt flowering as hard as the AG SkunkxNL, but they also were a couple weeks behind the SkunkxNL. So now most of these are about 2 months old. The sensi are about a month and a half old.

I know that the standard says that you have to switch to 12 off 12 on to induce flowering and anything over 12 will keep them in veg, simply put. Its my belief that light duration is not the only factor in when a plant determines its time to flower or not. I think that light duration, light spectrum, environmental stressors, and age of plant all play a factor. I mean I cant explain it any other way these bitches are full on flowering under 14 hours light, 6AM-8PM

This is how I do it normally is slowly reduce the light as I get closer to flipping. Ive done it for years and none of my photos flowered under 14 hours light, which leads me to believe that its their age. Ive never had to do it like this before keeping them small for a month and a half before transplanting, so this is the only difference that I can see. They did get pretty stressed out at certain points with super high temps, or the gnats, or when I accidentally grabbed the wrong bottle and they got overfed and burned. Maybe the stress had something to do with it but I dont know. I planned on vegging these another 3 weeks and over the three weeks I would drop the light hours down slowly till I got to 12/12 and then later in flowering reduce slowly till they are under 9 on 15 off. I just super cropped them last week which sucks cause apparently thats when they decided to flip themselves into flower.

Also these plants are exhibiting strange behavior. The SkunkxNL turn their leaves sideways after about 9 hours light. These are under 3 360 watt LED lights in a 5x10. I wonder if because they were under that weak 90 watt 3 foot long led for so long that they somehow adapted to low light conditions and then when put under powerful lights it was too much? Either way I dont know whats going on but this is proof that cannabis plants flower under 14 hours light and that light duration may not be the only factor in inducing flowering.

Ill attach photos below with dates along the way up until this mornings pictures.
 

Cpappa27

Well-Known Member
September 13th they were transplanted and put into the tent. you can notice I burned them with microbe brew when I meant to use Bembe. They healed just fine and blew up after.

IMG_20230913_170729844_HDR.jpg
 

The-Liquor

Well-Known Member
I'm pretty sure the actual flip point is closer to 14.5 and not 12/12. Strain dependent but the reducing of your light schedule is probably what did it.

12/12 is used to cover all strains and guarantee plants flower but the actual flip point is probably closer to 14/10. I can only speak for northern outdoor growers but if the flip point was truly 12/12 then we would be screwed as we have just in the last week or so dipped below 12 hours of sunlight.

Plants seem to know when the days are long or short. Or getting longer vs getting shorter. Outdoor plants typically go out after memorial day, the days are long enough and continue day by day to get longer until we reach peak daylight hours 15.5 (late June) and then the days decrease. Once the days reach around 14.5 hours of sunlight which seems to be late July in Michigan we see the stretch begin.

Now which indoor cycle 14/10 , 12/12, 10/14 is better for the ladies I have no idea. Recover does seem important but I doubt there is much difference flowering under 14/10 or 12/12 other then electric bill.
 

Cpappa27

Well-Known Member
I'm pretty sure the actual flip point is closer to 14.5 and not 12/12. Strain dependent but the reducing of your light schedule is probably what did it.

12/12 is used to cover all strains and guarantee plants flower but the actual flip point is probably closer to 14/10. I can only speak for northern outdoor growers but if the flip point was truly 12/12 then we would be screwed as we have just in the last week or so dipped below 12 hours of sunlight.

Plants seem to know when the days are long or short. Or getting longer vs getting shorter. Outdoor plants typically go out after memorial day, the days are long enough and continue day by day to get longer until we reach peak daylight hours 15.5 (late June) and then the days decrease. Once the days reach around 14.5 hours of sunlight which seems to be late July in Michigan we see the stretch begin.

Now which indoor cycle 14/10 , 12/12, 10/14 is better for the ladies I have no idea. Recover does seem important but I doubt there is much difference flowering under 14/10 or 12/12 other then electric bill.
Thank you, I do know that outdoors the actual hours are just that when they start to flip but indoors Ive used this way of reducing the light for years and never had this happen at 14 hours on. In the past some of my plants would start to flower around 13 hours but not 14. Ive kept mothers under 14 hours light as well and they didnt flower. This is just strange to me, Ive never experienced a full on flower at 14 hours in 10 years.
 

Cpappa27

Well-Known Member
This below is from Wiki. Perhaps cannabis plants have used to be day neutral before they evolved so there is still the gene, and the gene is activated under certain circumstances? Either way its just really interesting to me and makes me want to further experiment and see if there is ways to induce flowering in cannabis with higher hours like 16 or 18 hours by adjusting various environmental factors.


Along with long-day plants and short-day plants, there are plants that fall into a "dual-day length category". These plants are either long-short-day plants (LSDP) or short-long-day plants (SLDP). LSDPs flower after a series of long days followed by short days whereas SLDPs flower after a series of short days followed by long days.[11] Each plant has a different length critical photoperiod, or critical night length.[1]

Modern biologists believe[12] that it is the coincidence of the active forms of phytochrome or cryptochrome, created by light during the daytime, with the rhythms of the circadian clock that allows plants to measure the length of the night. Other than flowering, photoperiodism in plants includes the growth of stems or roots during certain seasons and the loss of leaves.

Day-neutral plants

Day-neutral plants, such as cucumbers, roses, tomatoes, and Ruderalis (autoflowering cannabis) do not initiate flowering based on photoperiodism.[18] Instead, they may initiate flowering after attaining a certain overall developmental stage or age, or in response to alternative environmental stimuli, such as vernalisation (a period of low temperature).[1][8]
 

Jylhavuori

Active Member
I ponder what are the longest hourly periods possible to initiate blooming by dropping daily light time, lets say in three months. (However steep steps) Never tried that.
 

Cpappa27

Well-Known Member
This might be far fetched but I had that male NLxSkunk in the tent while there was balls hanging all off it, until recently when I moved it about a week ago. Is it possible that female cannabis plants know when there is a male plant near them? Can they sense that and maybe sense how far along the male is? Maybe pollen did get released from that male when there was no flowers on any plants and the plants sensed that, which told them its time to flower? Like I said probably not, but it is interesting to me.
 

Jylhavuori

Active Member
This might be far fetched but I had that male NLxSkunk in the tent while there was balls hanging all off it, until recently when I moved it about a week ago. Is it possible that female cannabis plants know when there is a male plant near them? Can they sense that and maybe sense how far along the male is? Maybe pollen did get released from that male when there was no flowers on any plants and the plants sensed that, which told them its time to flower? Like I said probably not, but it is interesting to me.
I'm no expert in plants' intermessaging but I assume that plants touching each other in any way will enhance their communication. Then there are possible factors as you mentioned about pollen or other stuff like volative (air spread messaging) aromas/particles
 

conor c

Well-Known Member
It comes down to origin really look at the tropical stuff for example thats adapted to 12/12 most of the year near the equator and never more than 14 hours light some things are also more photo sensitive than others like semi autos there photo strains that are just really photo sensitive vs rather than real autos/ day neutral plants and yes they know if there is males in the same room or not for sure imo
 

Cpappa27

Well-Known Member
It comes down to origin really look at the tropical stuff for example thats adapted to 12/12 most of the year near the equator and never more than 14 hours light some things are also more photo sensitive than others like semi autos there photo strains that are just really photo sensitive vs rather than real autos/ day neutral plants and yes they know if there is males in the same room or not for sure imo
Could very well be. These from AG seeds are supposedly NL2 IBL and Skunk 1 IBL real F1. Could be the strain I guess, but the Sensi Skunk is also flowering just not as hard.
 

Charles U Farley

Well-Known Member
I know that the standard says that you have to switch to 12 off 12 on to induce flowering and anything over 12 will keep them in veg, simply put. Its my belief that light duration is not the only factor in when a plant determines its time to flower or not. I think that light duration, light spectrum, environmental stressors, and age of plant all play a factor. I mean I cant explain it any other way these bitches are full on flowering under 14 hours light, 6AM-8PM...

...but this is proof that cannabis plants flower under 14 hours light and that light duration may not be the only factor in inducing flowering.
You're quite correct, light deprivation is not the only factor in the initiaition of influorescence. Not sure about the light spectrum aspect because I haven't adjusted spectrum since I stopped using my Lumigrow 325 many years ago, but the age of the plant has a strong influence, in my experience.
 

conor c

Well-Known Member
Yeah well look at the gas lantern schedule many use that and swear by it theres clearly more to it than we know so far i remember cervantes spoke about it in his old book that some growers giving plants longer light hours than 12/12 they said they got a lil more yield but it retarded flower maturity somewhat too as the trade off
 

Cpappa27

Well-Known Member
Yeah well look at the gas lantern schedule many use that and swear by it theres clearly more to it than we know so far i remember cervantes spoke about it in his old book that some growers giving plants longer light hours than 12/12 they said they got a lil more yield but it retarded flower maturity somewhat too as the trade off
Its almost like the plant is in between veg and flower continuously.
 

conor c

Well-Known Member
Its almost like the plant is in between veg and flower continuously.
Well its ethylene levels and auxins that are tied to flowering and sex you will find the lower ethylene producing plants will be more sexually stable as well also thats why certain plants are a bitch to chemically reverse/yield no to little pollen even when its successful im sure its tied into blooming more than we understand currently
 
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