can flowering plants have more than 12 hours light?

Hi folks - I am wondering if flowering plants would benefit from 18 on 12 off. I am reading only the dark cycle determines the photoperiod but does anyone know for sure? I ask because autoflowering plants are left on 18 hours light all the time - so why can't you do that with normal plants and just add 12 hours dark every 18 hours? Or would they hermie and go back to veg?

Thanks!

Attached - Blue Dream at flower week 6 - LED from clone with SolarStorm 880 light.

Thanks, but doesn't answer my question. I'm wondering about 12 hours of dark and 18 hours of light.

Ah, ok thanks. That gives me a direction!

I never flip straight to 12/12 I go from 18/6 to 12/12 of a period of time. Reduce 30 min at a time every few days. Most every thing I have done this to start to flower at about 14/10. You could leave it there. I do not know of info that supports what you want to do. I have thought about it. I think it would work.

Have a go at it and maybe you will succeed. On the other hand if your new I would get a few grows done to learn the basics.

This is my fourth grow in the last year so while not 'new' I'm certainly still learning especially since each strain behaves differently. I'm running an experiment now with all LED to see what happens but everything is already different than it was with HPS. Felt pots have changed the way the plants take up water, it's changed the entire root structure as you probably know - so this entire grow is an experiment right down to the "fungally dominant" compost teas I'm using exclusively for food. So far, the lower heat has kept temps around 72 degrees during the day which helps slow the mites down considerably. There has been zero stretching so the flowering plants only grew another 6 inches which necessitates some bending of the buds around where you might not normally do that.

This grow represents the new world I have to live in if I want to do this for the next 20 years - HID is dead. I think.

Someone just tried that at gc and they barely went into flower and we're behind all the other plants

Good to know, thank you!

I have been dabbling and breeding and selecting traits that I like for 12/12 from seed. Sea of green. I would like to get to the point where I get an oz off each one.


I'm sure with a little time you could find the right ones for what you want to do.

Alot of plants like and can flourish under more than 12 hours but unfortunately once u got beyond that it can really mess up the shedule for peak hydro hours and such.so most people dont experiment much with light cycles.

And i know guys that run only autos and they grow best under 20/4

I'm surprised no one has brought up 730nm flower initiators...a couple minutes after lights off lets you flower on 13/11.

Red lights? What about it?

A 5 minute pulse of 730nm (far-red, not red) immediately after lights out, will increase effective night length by up to 2 hours.

A 5 minute pulse of 660nm (red) in sequence after the 730nm pulse will undo this and make it take as long as possible to get to sleep.

Interesting, never heard of that.

So what about slight variations in dark times - like 12 hours today, 5 minutes less than that tomorrow, 3 minutes more the next day, etc. The grounding is off in this building so timers don't work with the LEDS - I have to manually turn on and off and I'm in flower week 6.

Go get a timer.

I said timers don't work, they let power bleed through because of a grounding issue so the LEDS glow even when turned off.

even analog timers. They don't hold a charge. Dang that's like force flower outdoor. Uncover plants at 6 am and cover at 6 pm everyday.... the 730 sends the plant into its phytochrome state right away as if it were outside. (mimics sunset ) . The 660 deep red brings it out of the phytochrome state when lights come on. Normally indoors (no 730 at lights out) it takes 2 hours for the plant to go.into its phytochrome state. Utilizing 730nm, you can run longer days like outside. 14/10 or 13/11 and so on. Some strains take to it better than others. It also lengthens the finishing time by 2-3 weeks longer. 8-9 week strains end up taking 70-85 days. Like outdoor..

The problem is actually with the light; it tries to light up if it gets any power at all and the timers all bleed slight amounts, enough for the lights to glow when off. California Lightworks thinks it's not a problem and is solely an issue with the grounding here. And I'll say this building is so old it's exempt from earthquake standards so I accept that until I know different. That said, my smaller chinese LED has no issues.

Very interesting, I'll have to play around with that sometime. Thanks!