Finishing times, Photoperiod, Latitude, and how it all works!!

[MrFista]

Questions, why do informative threads always leave me with questions....?

I'm 36 S. I have recently vegged 2 strains under 20/4 and cloned them. There is a sat dom and indica dom. I have put clones from these into a translucent box in the greenhouse where they are getting 11 hours 40 minutes photoperiod (but add 40 minutes at least of actual light) - giving 12 hours light with increasing daylengths over 1 minute per day.

Will these root even?
Will these try to flower?
Will I get the desired result, vegging clones, without needing to set up a clone box?

Time will tell.

They went in 2 days ago.

 

[Guest]

Hello everyone,
Being an old goat on these forums, its rare to see a thread I will read all the way through. This is one of the better threads Ive seen in sometime, and the discussion it has sparked has been a very interesting read.

Not sure of the location... Spain somewhere, purportedly.

The strains were a little of everything he offered this last seed run/harvest. Runs the gamet, everything from full indica to full sativa.

Outdoor growing is such a squirrel... very hard to nail down. Every situation is SO drastically different from the next, with so many variables. I love discussing/pondering/pontificating/hypothesizing but the more I grow and learn, the more I think that each man/woman has to be THE expert in THEIR own area and circumstances.

Many of the things I've learned run in direct opposition to the advice I received from accomplished outdoor "gurus" here and at AN forums, etc. They told me X couldn't be done or Y wouldn't work or "good luck man... you'll be carrying 18 gallons of water a day!" ... but my own experimentation proved them wrong. They weren't "wrong" of course... they were wrong for my situation, but right in their situation.

But I ramble...

Wise words.

 

[AdmiralRed]

Good stuff!

 

[browndirt]

hey mate nice piece. Do you know of any strains that flower at the 4 or 5th inter node regardless of photo period?

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.

 

[Gunnarguchi]

hey mate nice piece. Do you know of any strains that flower at the 4 or 5th inter node regardless of photo period?

ive heard crosses with ak47xlowryder should be longer in vegetative stage than both lr1 and lr2 and more potent, otherwise you would be looking for photosensitive strains like Nigerian nightmare, female seeds Maroc or some of the nordic strains

NN should be schocked into flower otherwise its not that early
Maroc is early but yield and mold resistance isnt that great

the early nordic strains are what i would call semi af

not considered af but i know from personal experience that many of them will go into flower within 2-3 months no matter what light scheduale they are kept under

in my previous indoor room i tryed keeping mothers from Royal Danes, danish passion, leb27 and erocket x danish passion for a breeding project with more exotic strains, but they where all gone into flowering after a maximum of 3 month being kept under 18 hours of light
sucked for keeping as mothers but i guess thats the price of them going into flower so early outdoors.

 

[hoosierdaddy]

GrowDoc's Angel Dust is a Male only autoflower. I also think it's progeny exhibit this trait as well, ie...Bubbledust.
Males show full on flower at about 20 days or so. I got viable pollen from a male seedling that was 28 days from sprout, and under a single 26wattCFL.
If there are no preflowers on this strain by 20 days or so, it will be female.
I did not see any preflower at all with the fem I had, which was vegged for about 36 days.

 

[Gunnarguchi]

If we where to convert this theory into action regarding the strains heres a few examples

im at Denmark, 56 Northern latitude

if i took a September medium harvest strain like Royal Dane i can see that it starts if flowering medium July where its apr 17 hours of daylight here ( using a local almanak to determine daytime length)

if i used an October medium harvest strain like the Afghan nordic outdoor it starts its flowering medium August where theres apr 15 hours of daylight here

an 8 week strain that would finish medium November here would start to flower medium September where they daylight is 12 hours and 50 minuttes a day.

November medium finishers here would have a very hard time to fight the bad weather with lots of rain, fog and frost, so strains that starts there flowering at 15 hours of daylight would be preferred, and of course earlier

i dont know if each strain will perform similar all over the globe when it comes to the hours of daylight it takes to trigger them into flower.
any one has more knowledge on that?

if the hours of daylight each strain responds on to flower is the same all over the globe it would be great news as when can then just use a global daylight almanak and the finishing time and then be able to calculate at what time it will finish at our local area
of course this doesnt take into account would cause by frost and heavy rain but it should give a good indication none the less.

heres a world almanak
so you can compare daytime length from different locations and compare and estimate harvest times etc
http://www.jgiesen.de/daylight/

i used this almanak also to estimate when the Mazar I sharif would probably be harvested here. in Denmark
it finishes at December/January in Afghanistan and using the almanak to revert back 8 weeks i can se that it must begin its flowering stage at end September/start October
just before the daylight time in Afghanistan reaches 12 hours
end September is also the time of year in Denmark where we reach 12/12 which leads me to conclude that they will finish at about the same time both in Denmark and Afghanistan
December is way too late here so i guess it would either have to be grown indoor, in a Greenhouse or crossed with an earlier Afghan in order to finish at northern latitudes

 

[Murderapolis]

Ok what about here in Minnesota? Anyone ever grow OD here? When should I put them out and when Should I harvest them? Last time I tried it started to frost before the buds really got a chance to finish? But I grew that from seed at the start of summer around May. Should I pre veg till they get about 12inches tall then put them outside in May?

 

[Gunnarguchi]

if we play a little more with latitudes and day length from this almanac http://www.jgiesen.de/daylight/ and use it on some strain we know finishing dates and flowering periods on, theres some interesting data showing up

ive chosen Copenhagen, Denmark versus Vancouver, Canada BC
and the strains Royal Dane versus Nigerian Nightmare as i know the finish time for the Royal Dane here and ive seen grow report in Outdoor strainlist stating the finish time of Nigerian Nightmare at 49 n BC

the royal Dane is an 8 week finisher
not sure about the NN so i estimate it to 10 weeks after knowing its a sativa

if using the almanac and knowing the finish time and flowering time and finish date for one of the locations i can estimate it for the other one using the latitudes in the almanac

Royal Dane finishes at mid September in Denmark
being an 8 week strain i can see its starts its flowering cycle in mid July at 16,96 hours of light
using the almanac i can estimate the flowering and finish date for BC
now comes the interesting parts
according to the almanac BC doesnt have doesnt have any days at at 16,96 hours of sunlight, all are below with a peak at 16.212 hours at 16th of June
if this almanac theory would be very close to real conditions the RD would start budding shortly after having been transplanted outdoor in BC no matter what time of year
if we estimate that it will start budding shortly after peak time in mid June it would finish mid to end august in BC

if we take the Nigerian Nightmare into the almanac with a flowering time of 10 weeks and a harvest time and mid September in BC
we see that its starts flowering at apr 1st of July with a day length of 16.147 hours
in Denmark the closest we come is 16,139 hours of daylight at the 30th of July and with an 10 week flowering time it would harvest at mid October in Denmark

the Nigerian Nightmare is special as its told to be very photosensitive and could be shocked into flowering by being kept under 24 hours of light and then brought outside where it should start its flowering cycle right away due to a combination og shock and shorter day time

im not sure it would react so in Denmark as the days gets longer in a steeper angle than in BC but it remains to be tested, but maybe it would turn revert into vegetative stage here

since the Royal Dane as an example is also very sensitive and will often flower under 24 hours of light after a period of being kept indoor, theres a chance that the royal Dane and other early Nordic genetics would act the same way in BC and similar places

remains to be seen of course how much of this theory that be can converted to outdoor conditions in different locations with different latitudes and day length, but an interesting subject i think.

 

[North]

Here's a very usefull tool for all you outdoor lovers, I've had it bookmarked for awhile and forgot to link it sooner.

http://solardat.uoregon.edu/SunChartProgram.php

it plots the Suns path in compass degrees and altitude, so you can stand at a potential plot with your compass and tell where the sun will be on any given date.

 

[Whobdobub]

This one might be useful you just put in the dates and it will tell you how many hours of light.

http://www.almanac.com/rise/index.php?searchtype=zip&month=8&day=10&year=2009&what[]=Sun&what[]=Moon

 

[neongreen]

First, I need to point out that the furthest southern tip of Spain is only about 36 degrees north, which is still a ways from tropical. Compare San Francisco California at 38 degrees north and also consider that most of the southern 1/3 of the USA lays below 36 degrees north.

He might have been in the Canary Islands, which is Spanish territory. In fact, I think that is very likely. That would put him in a sub-tropical zone, about 28 degrees north of the equator, which is comparable to Orlando, FL. I believe the day length at that latitude varies between about 8 and 14 hours.

 

[BACKCOUNTRY]

Indeed! Dignan probably mixed that up a bit, perhaps not knowing where the Canary islands were. I'm sure a Canary islander would identify himself as a Canary islander rather than as Spanish(I think they are fairly independent).

 

[neongreen]

It would depend on who you asked I think. The native inhabitants that have been there for many generations came from Scandinavia originally, and they would probably refer to themselves as "Canarians", but there are also many relatively new arrivals from mainland Spain, and I suspect they would consider themselves "Spanish" first and foremost. I could be wrong though.

Raco would be the man to ask about this, and the story surrounding it. I'm sure he could offer some insight anyway.

 

[jakeh]

Backcountry,
I've got 3 feminized dp powerplants going at the moment. This is what dutch passions website says about them: "Powerplant (mostly Sativa) was developed by us in 1997 from new South African genetics. This strain has been inbred only, never hybridised. Very rich in THC. It is a strain with an enormous grow potential. Indoor as well as in a greenhouse the plants have an enormous yield. Indoors flowering starts already one week after turning back the lightcycle to 12 hours. Outdoor, flowering starts late, but the plants ripen very fast. This variety is very uniform. Strong “up high”, very soft smoke."

Of the 3 plants 1 was dug up by an armadillo, 1 was snapped in half by an armadillo and the other is fine. Overall I am very pleased with the strain. The dug up plant looked like nothing had ever happened after 24 hours and the broken plant mended in 48 hours with a splint. I've had plants that were stressed that went into flower early so my armadillo plants did not surprise me but they all are flowering. They were planted in late March and put into small pots on april 1. The most healthy and vigorous is currently 5' 6" and the others are 2' behind. The nodes began alternating 2 weeks or so ago. The joint of the side branches junction with the main stem as always showed the first preflowers but now the floral clusters are up and down the side and main branch. Durban, S.A. is at 29.5degress south in lattitude. I am within a couple degrees of that on the north side of the equator. It is supposed to finish the 2nd week of oct with an 8-9 week flower time. That flower time again is supposed to start late according to dutch passion. As you can see I am way ahead of that schedule. I am quite ok with it but surprised at the difference in breeder description and what I am experiencing first hand. I've got 8 himalaya gold that granted are 3 weeks younger but they have not even started preflowers and they are supposed to finish at the end of sept. What are your thoughts on my situation and have you experienced anything similar? Any input would be greatly appreciated.

 

[Huey69]

Just wondering if anybody could give me some insist as to why this plant appears (or is) to be flowering. It was germinated April 1st along with 2 other females. This particular strain is Pine Mist, not positive on the parents, and it may even been crossed with something else, I don't know. The other two strains (lavender and a mexican bagseed) show no signs of flowering whatsoever...

So why is she flowering? From my understanding, since it was grown from seed, it should know the proper photoperiod, and not be flowering. Is it possible this strain is autoflowering?

 

[tamio]

Great READ Great INFO!!! Thank you all so much!!!

 

[bergerbuddy]

I would not complain... I'D BE VERY HAPPY!!!! means it should finish withou MOLD~~~

Sweet lookin plant!

 

[chefboy6969]

i am at Latitude: 43° 40' N (North of Equator) and 79° 24' W..basically in SW Ont Canada..and i grow outdoors with indoor seeds..I start them in March and sex them in May and put them outside June 1..then (hopefully) harvest by Oct 15...depending on the weather of course..I have grown Blockhead(very nice outdoors and finishes by Oct 15 and Reefermans Cherry Berry same finished by first week of Oct.. ..I grew Feds CTS x ISS and had to finish it up in a greenhouse it was done by Nov 15..I will never grow a long flowering sativa again..I like to try different plants...this year I have Chem dog and Old Mendo and a Kush strain and Kali Gum(Kali Mist x Bubble Gum)..The old mendo has started to flower..(BTW yesterday was 14/10) i counted today as day 1..it is in full flower mode now..the Chem hasn't started yet but all of them are stretching a sign of flowering...Hope this info helps..

I have been doing this for 3 years now and find depending on strains the plants usually start to bud by last week of August and by Sept 1 all of them except the sativa's have fully started...good luck to all

peace
Chefboy

 

[tamio]

So kewl!!!

So kewl!!!

This one might be useful you just put in the dates and it will tell you how many hours of light.

http://www.almanac.com/rise/index.php?searchtype=zip&month=8&day=10&year=2009&what[]=Sun&what[]=Moon

Thank you so much!