Force 12/12 outdoor

It’s genetics. I’ve seen research on this. Some trigger and will stay flowering up to even 9 hours or darkness and 15 hours light. That’s rare tho like less than 5% of cultivars tested. Then above 10 hours you start getting much more that are gonna stay in flower. 11 and above darkness is like 85-90 % of cultivars that will flower consistently. Now when you go above those in light hours - after flower has begun - you are “revegging” and it will cease flower growth and begin to grow shoots from the flower. I have a diary of this if you wanna check out the process closer. you might get lucky. It’s a genetics thing like I said.

Only by using a far red after lights out. So when you bring it in when you want to sleep, (the photochrome to stop/photosynthesis) to 13.5hrs during pre flower you need an (730nm IR "Far Red) This is the only way you can increase your flowering time. Good luck.

I have done this a few times. In my experience, once you start covering/uncovering, you need to continue doing so throughout. The plants can get very sensitive to changes and unless you are certain the natural lighting is below the threshold, it’s very possible for revegging or stress causing male flowers. I did not leave my plants covered all night, I got up before the sunrise to cover, in essence extending the night. Some people like to cover in the evening and then uncover after dark. Others will leave it covered all night, but I worry about humidity doing that. My best piece of advice is to remain consistent with whichever way you choose to do it. Good luck!

I have done this, but not with great success. As the days got shorter and shorter the pre-flowering was evident but it never quite flipped naturally. I put it in complete darkness for 48 hours and when it came out it was flowering. It went straight back outside and - as far as I can tell - it did not hermie when going back out to ~14 hours of light. However, the plant never really progressed from there, despite the quick flower. The weather was quite cold by this time, which didn't help, but I suspect the plant was a bit confused as well. The flowers were weak and I ended up chopping it down with no returns. That said, it is possible. I think you need the right genetics (Northern Lights would be a good start) and a greenhouse (for warmer temps later on and shield from rain). I also think it would help to create an contraption which could close the plants off to light and reduce them to 12/12. You could do this by hand (opening closing a cupboard door/tent) but I would worry that you'll miss it that one day (shit happens!) and hermie the plant.