switching lights from veg to flower

[rasta man]

I have lights off 6 hours..10 to 4 a.m...I want to move this group to another group that I am going to grow 12/12 from seed to finish..but I want to have lights off during the day in that group..so on at nite at 8 and off at 8 in the morning..any way to move the group that is on 18/6 day shift to the night shift without messing them up .. herming and such..perhaps on the switch just leave lights off from the 4 am cutoff , another 4 hours and just go from there..or is this gonna mess them up so bad that I should not do it..and figure out another way..

 

[DoubleTripleOG]

In my experience, it doesn't matter. You can take plants from any veg light cycle , and put them into flower. I personally would move them into the flower room, right after the lights come on @ 8. Then they will have an extra long day to soak in the light before their first "night" in the flower room.

 

[Farmer B]

I have lights off 6 hours..10 to 4 a.m...I want to move this group to another group that I am going to grow 12/12 from seed to finish..but I want to have lights off during the day in that group..so on at nite at 8 and off at 8 in the morning..any way to move the group that is on 18/6 day shift to the night shift without messing them up .. herming and such..perhaps on the switch just leave lights off from the 4 am cutoff , another 4 hours and just go from there..or is this gonna mess them up so bad that I should not do it..and figure out another way..

What ever your day starts at you should keep it and shorten the day. But the switch should have light off for 24-36 hours to lower certain hormones. Doing that your restarting them and should be fine.

 

[Jhhnn]

In my experience, it doesn't matter. You can take plants from any veg light cycle , and put them into flower. I personally would move them into the flower room, right after the lights come on @ 8. Then they will have an extra long day to soak in the light before their first "night" in the flower room.

Makes sense to me. Cannabis is actually a short day plant as described here-

https://en.wikipedia.org/wiki/Photoperiodism#Short-day_plants

It's not the day length decreasing that determines flowering but rather the night length increasing. Doing it your way would seem to avoid confusion altogether because the length of the day doesn't matter.

 

[DoubleTripleOG]

Makes sense to me. Cannabis is actually a short day plant as described here-

https://en.wikipedia.org/wiki/Photoperiodism#Short-day_plants

It's not the day length decreasing that determines flowering but rather the night length increasing. Doing it your way would seem to avoid confusion altogether because the length of the day doesn't matter.

And that's the way I have always thought of it. Day length in veg doesn't effect the plant in flower. In all my years of growing, the only thing I have ever seen extended daylight hours in veg do, is make certain strains who become rootbound, start to auto-flower. But I'm only speaking of 2 strains out of the 100 or more I have tried.

 

[Jhhnn]

And that's the way I have always thought of it. Day length in veg doesn't effect the plant in flower. In all my years of growing, the only thing I have ever seen extended daylight hours in veg do, is make certain strains who become rootbound, start to auto-flower. But I'm only speaking of 2 strains out of the 100 or more I have tried.

Sure. They autoflower because they're stressed & are driven by the biological imperative to reproduce while they can. Most varieties aren't sufficiently stressed under the same circumstances to react that way.

It's good to see somebody with much greater experience than my own confirm what the literature tells me. If we created a light cycle with a day length of 18 hrs, 12 light & 6 dark the plants wouldn't flower even though the light period is only 12 hrs. If we created a light cycle with a day length of 30 hrs, 18 light &
12 dark then the plants would flower because the night is long enough.

At least that's the way I understand it.