indoor to outdoor. photoperiod and flowering.

Hi!

As primarily an indoor grower, I think I probably miss the subtle changes that cannabis exhibits outdoors. Just wanted to throw some observations out there and try to learn something.

When the light cycle changes in Indoor it is like a step function; not gradual.

What I am wondering is this. For a plant that is outdoors, will the plant recognize a decreasing day time and begin flowering based primarily on the info of decreasing daytime? (regardless of the absolute number of hrs of daytime, within a limit)

In my area, the longest day is approx ~14 hr 45 min according to timeanddate dot com.

I have read that most cannabis starts the flowering stage when the day light drops to about 15 hr. I guess that is rule of thumb.

Last year, I noticed my cultivar was stretching and going into early flower during July when the day time was prolly around 14 hr.

They were put out 2+ months prior to the summer solstice. So, I submit (ok. I'm learning here) that when exposed to daytime cycles of less than 14-15 hr, the cannabis will not convert to flower stage when the daytimes are increasing. Does my math check out? Pls share what you experience and have learned.

Is this why it may not be necessary for plants destined for Spring outdoor planting to sync an indoor lighting schedule to the daytime schedule outdoors; because the plant will figure it out?

Like, can you we from an indoor 18/6 and dump them outdoors with a 11/13 that the day time is increasing even if presently only 11 hours? I don't do 18/6 so I won't know. I'm closer to 16/8.

Take care everybody!

I have this problem every year. I start them at 18/6 for around 6 weeks and put them out late May. They usually flower for about 3 weeks and then revert back to vegetative stage. It sometimes leaves the plant looking a bit shabby and in need of a good trim. Any help would be greatly appreciated!

thespaceman937 said:

I have this problem every year. I start them at 18/6 for around 6 weeks and put them out late May. They usually flower for about 3 weeks and then revert back to vegetative stage. It sometimes leaves the plant looking a bit shabby and in need of a good trim. Any help would be greatly appreciated!

Click to expand...

I have the same problem man, it’s like I’m forced to grow autos during the summer.

Thanks for the feedback on experiences.

[Last year] After prematurely inducing flowering with the short day time before the equinox, I later impacted flowering again after the equinox with light leaks from windows on one side of the house.

So this year we are purposely using the light leak from the house at night to keep the plants from flowering up until the equinox. At that point we will cover those windows at night. That's the theory, fwiw.

Small solar light you can put with them that charges in daylight and comes on when it gets dark could trick them into staying “awake” and out of flower. It won’t do much in the way of photosynthesis (though, I dunno- I have a floodlight type that hurts your eyes; looks like LED’s), but should help “lengthen the day”.
I ran an extension cord out to a plant I had and put a nice light over it last year. It was covered over the top with a small glass window piece and had corrugated plastic around the sides. Had it on a timer and a good LED bulb. When it came on at 3am it looked like a cool, big lantern in my yard.
But, for cheap and easy just put a solar pathlight or something similar above or near it.
My friend uses Christmas lights!

I have started my plants inside under regular florescent Grow tubes (4 x 35 w) in the basement laundry room along side my tomato plants. I move them outside each day if the weather is agreeable. When all chance of frost is gone out they go. I have never tried to sync the sun to lamp conditions. As far as I know the plant outside will do what it wants to do when it is supposed to it. I know it is a new game altogether when you have the option of growing indoor but you also get to control the conditions. I saw a thread somewhere and the post was calling indoor grown plants "designer weed". At first I laughed about, then I read posts about people breeding cross strains and making up names for the new strain they made.

I started early for outdoor so my first round is going to be partially indoor-light raised. I do this throughout the season, but use more electric-light (for obvious reasons) during the darker months. When I move them outside I put them in my greenhouse semi-shaded for part of day by other plants/obstructions, or somewhere outside that is similar as long as it’s not too windy, and it’s above 70F. The strains I have now seemed to adapt very quickly. Durban Poison and Kwazulu; Sativa landrace. However- I had a very healthy and happy White Widow that did not like the change and quickly changed course. She is not with us anymore...
So, yeah, if you can, start taking them outside and either use a solar or electric light to trick it into thinking the days are longer,
Or- put it back inside under more light at night.

I think most* indoor photoperiod plants are more susceptible to hermaphroditism from light-leaks during flower, than outdoor raised, because studies have shown that as the sunlight starts to fade plants begin storing energy in their roots to use during the nighttime. With indoor plants, the transition is literally night and day, unless you are including a dimming aspect (*that is what this asterisk above is noting), so perhaps they become used to “awakening fully” with any appearance of light. Outdoor also adjusts to the moon and ambient light in the sky.
Think of how you would feel under such conditions. Much easier to fall and stay asleep when lights out/on is gradual and you are used to ambient light in the sky, rather than in a room that suddenly darkens, and suddenly brightens. Also, if you were in a pitch-black room and a pinpoint of light was poking through and catching your eye, it could be very distracting.
I’m flowering a few plants now, in a greenhouse, with nothing more than a couple bags pulled down over their tomato cages, with the bottoms still open. Only temporary until I make a bigger system, but they are happily throwing out pistils. Also, still at about 13/11 light/dark days so pretty easy dawn dusk transition.
Hopefully some of this is helpful for you.

MAGpie81 said:

Small solar light you can put with them that charges in daylight and comes on when it gets dark could trick them into staying “awake” and out of flower. It won’t do much in the way of photosynthesis (though, I dunno- I have a floodlight type that hurts your eyes; looks like LED’s), but should help “lengthen the day”.
I ran an extension cord out to a plant I had and put a nice light over it last year. It was covered over the top with a small glass window piece and had corrugated plastic around the sides. Had it on a timer and a good LED bulb. When it came on at 3am it looked like a cool, big lantern in my yard.
But, for cheap and easy just put a solar pathlight or something similar above or near it.
My friend uses Christmas lights!

Click to expand...

I have used the light from our laundry room to gas lanter my plants. It just needs to be bright enough to keep them awake.
That being said, this year I'm moving them to the hoop house known as, "Parts Unknown!" earlier and hanging 600w metal halide lights in there too. They will come on at dusk for heat and to keep them out of flowering. And the sun can take care of most of my lighting needs for free!
I run them at 24 hours of light this time of year to keep the temperature in the basement stable. So I will continue that until mid June and be able to spend less doing it this year.

@JimmiP
I just moved some clones to a hoop house that is barely used, too. Also put some in a fresh-amended garden bed to be raised organically with veggies. Need to put up some solar lights for the greenhouse today. Might run a cable out there and hang some LEDs.
Not going to supplement the veggie companions with light- at 12hrs40min between sun being at the horizons, but that doesn’t count the atmospheric light before and after sunset, so I think it’s fine- “organic”, anyways, haha.
It’s going to be a good year.

zeem said:

Hi!

As primarily an indoor grower, I think I probably miss the subtle changes that cannabis exhibits outdoors. Just wanted to throw some observations out there and try to learn something.

When the light cycle changes in Indoor it is like a step function; not gradual.

What I am wondering is this. For a plant that is outdoors, will the plant recognize a decreasing day time and begin flowering based primarily on the info of decreasing daytime? (regardless of the absolute number of hrs of daytime, within a limit)

In my area, the longest day is approx ~14 hr 45 min according to timeanddate dot com.

I have read that most cannabis starts the flowering stage when the day light drops to about 15 hr. I guess that is rule of thumb.

Last year, I noticed my cultivar was stretching and going into early flower during July when the day time was prolly around 14 hr.

They were put out 2+ months prior to the summer solstice. So, I submit (ok. I'm learning here) that when exposed to daytime cycles of less than 14-15 hr, the cannabis will not convert to flower stage when the daytimes are increasing. Does my math check out? Pls share what you experience and have learned.

Is this why it may not be necessary for plants destined for Spring outdoor planting to sync an indoor lighting schedule to the daytime schedule outdoors; because the plant will figure it out?

Like, can you we from an indoor 18/6 and dump them outdoors with a 11/13 that the day time is increasing even if presently only 11 hours? I don't do 18/6 so I won't know. I'm closer to 16/8.

Take care everybody!

Click to expand...

All that needs to be done here to stop premature flowering is leaving a patio light on when the sun goes down. Have the plants close to it. I leave mine on over night.

I see my plants begin to stretch when the sun time begins to shorten too around 14 and half hours.

Ive noticed clones are too finicky for indoor to outdoor transition unless you match the light down to the wire. my longest day is Round 14:30 or something but with it increasing i have my plants at 15 hours as the time goes from 11-12-13 ill decreSe to match im praying for a smooth transition because a revegg is such a buzzkill

Hi John. Is it is primarily the reveg you refer to as the finicky part?
I might not know what optimum performance looks like.
Thanks very much!

I start mine inside, veg for 6 weeks then flip to 12/12 a week or so later when they are white hairs i stick them outside to finish flowering. I'm in florida. So far they have never reveged on me.

I am trying to do this in Arizona and have been putting out plants during day and back inside under lamps all night. They are handling the 90’s here pretty well. All clones 3 started in dec and 3 started in January and couple more in March. All look good big vegging out but a couple grandddady purples look puny after day outside even under shade clothes. It like it’s too much for them. They get droopie. May 20th is my full 14.50 hours here. I do not want them going back into flower (buzz kills for realz) and back into veg again. I may have to rig up lights on the shade covering. It’s my 1st grow and it’s legal here now! Big learning curve for me. I want evaporative cooling greenhouse !