Where's the rule that says you have to flower under 12/12

[symbiote420]

I consider myself a common sense grower I look at nature first then try to replicate her as much as possible in my grow room, almost everybody uses 12/12 like it's the law, Being a grower aka a "natural law breaker" I feel I might need to shed some light on this matter for newbs and old heads alike.

Ever pay attention to outdoor crops in nature? 12/12 doesn't occur till October, that's basically harvest time for most, so if some plants are fully harvested before Oct., why use 12/12 as your indoor photoperiod for flowering?
One of the things I know about nature is she shouldn't be rushed too much, all strains have a specific photoperiod and finding your plants proper photoperiod will increase every aspect of her.(taste, yield, high, etc.)

I personally use the 12.5 on 11.5 off schedule, but that's only because I run different strains. I have a friend who runs 13.25/10.75 for his Afghans, they take about 11+ wks to fully mature but that's some of the best shit I've ever inhaled/exhaled. So why is everybody teaching 12/12 when it comes to flowering instead of a more strain specific photoperiod? I believe this is one of the major reasons why a lot of strains suck when we grow them out. What do you feel about this?

 

[Seamaiden]

I don't view it as a rule, I view it as a guideline. I think that with how muddled the genes of cannabis are currently it would be extremely difficult, at best, to go with a very strain specific photoperiod. If we were working with landraces, perhaps.

 

[Sea Of Green]

*Copy & paste from a random website*

Does 12/12 mean anything outdoors?
Often I have seen new members(or members mostly experienced in indoors) post threads asking when 12/12 occurs outdoors. Often they say they are looking for the time of the season when their plants will start blooming outdoors, many times they are trying to use this date(Sept 21 Equinox) plus the strains indoor finishing time to determine the outdoor finishing time.

But of course it doesn't work that way, we know that most strains have started blooming long before Sept 21st, but there is even more reason why indoor finishing times can't be applied outdoors.

One thing to realize is that as the day lights length shortens, the plants speed up their blooming, since most plants start blooming long before 12/12, outdoor plants will take longer to set into blooming and to finish than their indoor grown sisters would. So basically, unless you live very near to the Equator, indoor finishing times will not be applicable outdoors.

Finishing times, Photoperiod, Latitude, and how it all works!!
We all know the basics of vegging and blooming Cannabis..... when the day is long and the night is short the plant concentrates on vegging(growing), when the day length shortens enough, the plant starts to bloom.

But how does all this work?
Why does the same strain finish at different times in different parts of the world? Does 12/12 really mean anything outdoors? Why is Latitude(or "Lat") so important to some growers? What is a "Auto-flowering" plant?

Lets get into the meat of the subject shall we?..............

Photoperiod
The first thing to cover here is Photoperiod- Photoperiod is the ammount of time there is light in a 24 hour period. In Cannabis growing, Photoperiod is typically shown like this- 12/12 or 16/8, or 18/6, etc. The first number is usually the length of the lighted period, the second shows the balance of the 24 hours that is dark.

Outdoors the sun controls the Photoperiod. Its length changes through the seasons according to the movements of the sun in the sky, a matter of fact it causes the change in seasons. This brings us to......

Photoperiodism
Photoperiodism is the reaction of many flowering plants(including Cannabis) to changes in Photoperiod. Plants that experience Photoperiodism have pigment cells called Phytochrome that monitor the ammounts of light being absorbed by the plants(specificly the red end of the spectrum), and the length of day. Signals from the Phytochrome tell the plant to do many things, including to grow, bloom, and in the case of some trees, to loose their leaves and go dormant in Autum.

Most of these plants fall into three catergories concerning blooming times, that being- long day plants(blooms as day gets longer), short day plants(blooms as day gets shorter), and day neutral plants(blooming is not according to light cycles).

All Cannabis varieties are either "Short day", plants or "Auto-flowering" (known as "Day neutral" outside of the Cannabis community). So called "Auto-flowering" plants do not seem to take their blooming cues from the sun, and thus should be considered "Day neutral", as most seem to be geneticly programmed to bloom according to age insted.

----------------------------------------------------------------------

The Sun, Latitude, and why the same plants finish different times at different points on the globe

The year as we know it is basicly the time it takes for the Earth to make a complete loop around the sun. As the Earth makes this loop it shifts on its axis, so that either the northern half or southern half(Hemispheres) have the longer photoperiod.

The shortest day of the year is called the Winter Solstice, this day occurs on December 21st in the northern half of the world, on the same day in the southern hemisphere they will have their Summer solstice, the longest day of the year. On June 21s it will be reversed, with the longest day of the year in the north(Summer solstice), and the shortest day in the south(Winter solstice).

Two days of the year are known as the equinoxes, one occurs March 21st and one on September 21st. These days represent the halfway point between the longest and shortest days of the year, on these days the day length is almost exactly 12/12 all over the world. If you are in the Northern hemisphere, Mar. 21 is the first day of Spring and September is the first day of Autum, reverse these dates in the southern hemisphere.

Latitude
Latitude is the east-west lines you see on a globe or map of the earth, they are spaced about every 111 Kilometers starting at 0 degrees at the Equator, and graduating north and south from there (every 111 KM) to the north pole(90 Degrees North) and South pole(90 Degrees south).

Here is a link to Wikpedia explaining Latitude-

Latitude

At the Equator the length of day doesn't change much from month to month, at both Solstices the length of day is about 12 hours, at both Equinoxes it is about 12 hours, almost perpetual 12/12.

Now lets take a look at Portland Oregon, this city sits near 45.4° N, which is about exactly halfway between the Equator(O°) and the North pole(90°N).
At the Winter solstice, the length of day is 8h 41m, at Summer solstice the day length is 15h 41m, and at the Equinoxes it is 12h 12m.

And now lets look at Anchorage Alaska, this city sits at 61.2° N, a little over 2/3 of the way to the North pole(90° N) from the Equator(0°).
At the Winter Solstice the day length is 5h 27m, at Summer solstice the day length is 19h 22m, and the Equinoxes are 12h 18m.

As you move away from the equator(either north or south), you see more distictness between the seasons and the length of days during those seasons.

Generally the closer you are to the Equator, the less difference there is between the length of day on the Solstices(the longest and shortest days of the year.

The further you are from the Equator, the more difference there is in length of day between the Solstices, making the Summer shorter and shorter, and the longest day of the year longer and longer the further you go from the eternal 12/12 of the Equator.

Here are the Latitudes for a few North American, European and Australian cities to show a example of the vast differences in latitude-

Darwin, Australia-12.4° S
Miami, Florida-25.8° N
Houston, Texas-29.7° N
Los Angeles, California-34.1° N
Atlanta, Georgia-33.9° N
Canberra, Australia-35.3° S
San Francisco, California-37.8° N
Reno, Nevada-39.5° N
Naples, Italy-40.8° N
Chicago, Illinois- 41.9° N
Boston, Massachusetts-42.4° N
Toronto, Ontario-43.6° N
Ottawa, Ontario-45.3° N
Seattle, Washington-47.6° N
Vienna, Austria-48.2° N
Vancouver, British Columbia-49.2° N
Calgary, Alberta-51.1° N
Warsaw, Poland-52.2° N
Amsterdam, Netherlands-52.3°
Edmonton, Alberta-53.3° N
Anchorage, Alaska-61.2° N

The Photoperiod sensitive strains of Cannabis are each geneticly programmed to start blooming when day shortens to a certain length*.
When these various strains are bred, they become acclimated to that latitudes photoperiod, they are bred to bloom and harvest before that areas climate becomes too cold and dark(or wet), usally to avoid major mold problems, or harsh freezing weather.
*Many experts agree that it is actually the length of the dark period that matters to plants.

When you take a plant that was bred in one location, and move it to a similar Latitude, say from 42° N to 43° N the plant should harvest at nearly the same time. But if you take a plant from 42° N to 50° N, its possible that the plant may not harvest early enough to beat Winter further up north.
__________________________
Here is a chart comparing the length of day for 4 areas, over the year. The first number is the length of day(meaning sunrise to sunset), the second number includes the twilight time before sunrise and after sunset(basicly the total length of visable light)-

----- Houston, TX 29.7°N--------Humbolt county, CA 40° N------Eugene, OR 44.1°N--------Vancouver,BC 49.2°N

Dec 21--10h 14m/11h 07m------------9h 22m/10h 23m--------------8h 52m/9h 58m--------------7h53m/9h 27m

Jan 21--10h 33m/11h 24m------------9h 51m/10h 49m--------------9h 26m/10h 30m------------8h 54m/10h 05m

Feb 21--11h 19m/12h 07m-----------10h 58m/11h 53m-------------10h 46m/11h 45m-----------10h 31m/11h 36m

Mar 21--12h 58m/12h 56m-----------12h 10m/13h 04m-------------12h 11m/13h 09m-----------12h 13m/13h 16m

Apr 21--13h 03m/13h 52m-----------13h 29m/14h 25m-------------13m 44m/14h 45m-----------14h 04m/15h 12m

May 21--13h 45m/14h 57m-----------14h 31m/15h 33m-------------14h 45m/16h 06m-----------15h 34m/16h 53m

Jun 21--14h 03m/14h 57m-----------15h 57m/16h 05m-------------15h 30m/16h 43m-----------16h 14m/17h 40m

Jul 06--13h 58m/14h 52m-----------15h 00m/16h 06m-------------15h 22m/16h 34m-----------16h 04m/17h 28m

Jul 21--13h 45m/14h 57m-----------14h 31m/15h 33m-------------14h 45m/16h 06m-----------15h 34m/16h 53m

Aug 06--13h 26m/14h 17m-----------14h 09m/15h 10m-------------14h 24m/15h 29m-----------14h 53m/16h 06m

Aug 21--13h 03m/13h 52m-----------13h 29m/14h 25m-------------13m 44m/14h 45m-----------14h 04m/15h 12m

Sep 06--12h 36m/13h 24m-----------12h 53m/13h 48m-------------12h 58m/13h 57m-----------13h 09m/14h 14m

Sep 21--12h 10m/12h 56m-----------12h 10m/13h 04m-------------12h 11m/13h 09m-----------12h 13m/13h 16m

Oct 06--11h 43m/12h 31m-----------11h 32m/12h 27m-------------11h 28m/12h 26m-----------11h 21m/12h 25m

Oct 21--11h 19m/12h 07m-----------10h 58m/11h 53m-------------10h 46m/11h 45m-----------10h 31m/11h 36m

Nov 06--10h 52m/11h 42m-----------10h 13m/11h 11m-------------10h 00m/11h 01m------------9h 35m/10h 43m

Nov 21--10h 33m/11h 24m------------9h 51m/10h 49m--------------9h 26m/10h 30m------------8h 54m/10h 05m

Dec 21--10h 14m/11h 07m------------9h 22m/10h 23m--------------8h 52m/9h 58m-------------7h 53m/9h 27m

Length of day Vs. Length of visable light
When you see people describe outdoor Photoperiod, they often use the "Length of day" to describe it. "Length of day" is defined legally as the time between sunrise and sunset, the problem with using this figure is that it doesn't count the visable light known as "Twilight", that occurs before sunrise, and after sunset, the day may actually be 1 hour(or more) longer!
Cannabis plants do have a cut off point where they no longer consider fading light as "day", I am sure this tolerence point is different for each strain grown. Obviously a full moon is not bright enough to affect Cannabis plants, but who really knows where cut off is?

 

[Capulator]

great info.

 

[Texas Kid]

12/12 in nature happens about the same time as the fall equinox, this year in Colorado it is Sept 23 I think when we go full on 12/12..declining days do a little but the photo-period is pretty not in full effect till then

Daylight savings time change is a good benchmark for harvest out here or a week before, I think it is November 6 this year so i am lookin to pull that week which also coincides with the first hard freeze out here on the open range

Tex

 

[Seamaiden]

And then there's the issue of equatorial regions, whose daylight periods average 12/12.

 

[Darkstar]

Outdoors is a gradual process.
Indoors you're forcing flowering.

 

[Sea Of Green]

Outdoors is a gradual process.
Indoors you're forcing flowering.

Exactly.

A good analogy would be trying to achieve top speed in a vehicle. You can do it two ways.

1. Gradually push the accelerator pedal to the floor.(Like flowering outdoors, or gradually reaching 12/12)
2. Floor it off the line.(Like flowering indoors, 12/12 from the get go)

One of those ways will, obviously, get you to the vehicle's top speed sooner.(Make your plants finish flowering sooner)

 

[sedate]

A good analogy would be trying to achieve top speed in a vehicle. You can do it two ways.

1. Gradually push the accelerator pedal to the floor.(Like flowering outdoors, or gradually reaching 12/12)
2. Floor it off the line.(Like flowering indoors, 12/12 from the get go)

I generally switch mature plants in veg - awaiting the move into the flower room - to 18/6 at something like 24" - I find plants generally make the transition into flower quite a bit quicker - and I think a dark cycle can help a bit with overall plant vigor.

 

[symbiote420]

The post pasted by Sea of Green is exactly what I'm getting at, the last part where it talks about the "cut off point" for cannabis and who really knows it. If the cut off point for the strain you are growing is about 10 or 14 hours and you're giving it 12, what effect is it having on that strains potential? I gave my buddy that philosophy and he ran with it! What we have noticed with his Afghan Dreams even though the flowering time was increased a little from 10 to 11 weeks that shit is better than his 12/12 runs with her in every way, more trichomes , bigger buds, the looks and the smoke are killing the 12/12 so much people think he is growing another strain, then I started reading how some people flip the light cycle on their sativas from 12, down to 13 or 14 hrs., I started doing mine 11.5 because I run a lot of different indica/sativa hybrids and I didn't know how the sativa genes in the plants would like it if I went lower, but all my plants have responded well to this I'm running Super Lemon Haze, Larry OG, and Sour D under it and they excel over other peoples who I've tried that do theirs under 12/12 with really no difference in flowering time, I will add to that when I grew some Haze Skunk (mostly sativa) they sucked under 11.5 off, and we all know that's a pretty good strain. If I ever get enough room to grow that stretchy focker again Imma redeem myself and use a more appropriate photoperiod to see what happens?
The seed companies really would do the growers of the world a great justice by finding the actual photoperiod for each strain they sell, IMO.

 

[SLO Grown]

"Where's the rule that says you have to flower under 12/12" Great question! It's just a suggestion. If you notice when one grows outdoors, high Indica strains start to flower at 14 hours. So experiment.....

 

[Sea Of Green]

The post pasted by Sea of Green is exactly what I'm getting at, the last part where it talks about the "cut off point" for cannabis and who really knows it. If the cut off point for the strain you are growing is about 10 or 14 hours and you're giving it 12, what effect is it having on that strains potential? I gave my buddy that philosophy and he ran with it! What we have noticed with his Afghan Dreams even though the flowering time was increased a little from 10 to 11 weeks that shit is better than his 12/12 runs with her in every way, more trichomes , bigger buds, the looks and the smoke are killing the 12/12 so much people think he is growing another strain, then I started reading how some people flip the light cycle on their sativas from 12, down to 13 or 14 hrs., I started doing mine 11.5 because I run a lot of different indica/sativa hybrids and I didn't know how the sativa genes in the plants would like it if I went lower, but all my plants have responded well to this I'm running Super Lemon Haze, Larry OG, and Sour D under it and they excel over other peoples who I've tried that do theirs under 12/12 with really no difference in flowering time, I will add to that when I grew some Haze Skunk (mostly sativa) they sucked under 11.5 off, and we all know that's a pretty good strain. If I ever get enough room to grow that stretchy focker again Imma redeem myself and use a more appropriate photoperiod to see what happens?
The seed companies really would do the growers of the world a great justice by finding the actual photoperiod for each strain they sell, IMO.

I see what you're saying. There's lots of theories about which flowering photoperiod is better indoors. I'm fine with 12/12 myself. I would bet that, for the majority of indica based strains atleast, it's the fastest and most productive method. Which is first priority when it comes to indoor growing. And is probably why 12/12 has become the worldwide standard. Time = $. If you can get slightly bigger buds running more hours of light, and/or spending more days flowering the plant, either way it's money coming out of your pocket when you pay the electricity bill. And the longer it takes you to finish a plant indoors the more money you pay in not just electricity, there's also more water and nutrients that need payed for too. Turn-over rate needs to be considered as well(how many crops can you grow in a year). The faster you can get your next crop started the better. Those are the main reasons why you want plants grown indoors to finish ASAP. So, if you want a longer growing season/more buds/bigger buds, grow outdoors! It's cheaper, easier, and you can grow indoors at the same time if you want!

Bottom line: The best way to achieve outdoor results is to GROW OUTDOORS.

That's my view on it. However, I'd be willing to experiment with it a little too, if I could afford it financially. But...I can't. Gotta stick with what I know works.

And in a sense, seed companies do give you the photoperiod for each strain. When they tell you it takes x many weeks to finish indoors, that is based on how many weeks at 12/12.

But the part where it mentions the cut off point is in reference to when does the plant consider it to be no longer daylight hours. So the question really is how dark does it have to get for a cannabis plant to react to the level of ambient light as if it were night? Or when does the plant go to sleep? That's not going to be when it's "pitch-black" necessarily, since there's always some ambient light at night(starlight, moonlight, meteors, planets, comets, etc.). There will be a certain number of photons in the PAR spectral range hitting the plant in a given period of time that will be the threshold for what it takes to wake the plant up, and/or keep it awake. Which is a question best left unasked/unanswered IMO. Total blackout is still the safest bet.

 

[symbiote420]

If everybody that grew was worried about electricity only, no one would grow sativas indoors. The majority of growers I know are more concerned about producing the highest quality product they can, unless you're commercial then you may be more concerned with time tables and cost IMO. Any home grower concerned about that should just use a smaller wattage or grow outside. I'm growing for ultimate quality and that does cost a little more some way or another.

 

[Sea Of Green]

I hear ya. I'm just talking strictly economics though. Not quality per say. On that note I can't say too much more. Except times are rough for some these days, myself included. I have a very limited budget(limited income). Anywhere I can find to trim the fat, it get's trimmed. Shit's getting more expensive by the day. EVERYTHING! So, I've learned how to grow more for less, or atleast an equal amount for less. And if I could tweak my plant's yields, or quality for that matter, to get any more for my money I would. But I've got those areas dialed in just about perfect after getting close to 10 years now trying just about everything there is to try.

Anyhow if anybody can do it like I do but better, quicker, or for cheaper, I'd sure like to know how. As such I've got a constant supply stream of perfectly grown, excellent quality, cheaply self-produced medical marijuana. Who could ask for more?

BTW, I don't grow anything that's more than 25% sativa ideally. I'd like to, but if it doesn't finish fast, it's just not as economical indoors IMO. High potency, high flavor, high yielding, fast finishing strains are NOT a myth(I should know, I grow one). And outdoors in my region any plant more than 50% sativa could end up being a catastrophic failure(if it starts raining in the beginning of October you're fucked...because it ain't stopping 'til May or June). So I like to stick to 75%+ indica strains there too usually.

 

[theTinker]

Glad to see a thread like this now. Im approaching my last days of flowering and instead of 12/12 I used 11 on, 13 off. Just to try speed things up.. Definitely wont be repeating it. Airier smaller buds. they just lack the size i have been used to seeing on this strain.
*However. They have matured faster. Im seeing lots more orange hairs and buds approaching end of cycle at least a week ahead of usual scehdule.If i can afford to. next cycle will be 13 on, 11 off. Hopefully ill get the inverse effect. Slightly longer, but with a big pack on the yeild.
I flip depending on height of canopy so Flowering time is all i can manipulate after that.

I think 12/12 rule is great though. It works for every grower. Of course its not optimal for alot of strains. However, Until a grower has multiple grows of the same strain in the same conditions under thier belt, its difficult for most to experiement with. Everyone should start with 12/12 and try find the best for thier own strain and conditions over time.

 

[symbiote420]

I wish the seed breeders would step out on this a little more, if I had the space most of them have, the more information I could learn at one time with a particular strain, that would be priceless!! IMO a true breeder should know almost everything about a strain before it hits the market and that'll be a big plus to start including preferred photoperiods for the outdoor and indoor grower alike.