Change 12/12 back to 18/6


So i have a jack herer auto it was 35 days old and no pistils. I decide it to change 12/12 to show the pistils. After changed the light it showed about 3 days, and she is flowering.

Can j change the light back to 18/6 or she will be hermie ?

1 Like

I’d love to know the answer to this as well (relating to switching back for autos)! @dbrn32 ?

This Goldleaf has been in veg for almost 14 weeks, so it was suggest I switch to 12/12 from 18/6 to induce some flowering (which it did).

Well, these are the new autos zkittlez and gelato that are also in the tent and actually started showing pistils pretty early on (before the switch). I’m moving from a 2x4 to a 4x4 tent soon. Would switching back to 18/6 give the little ones more time to veg but keep the Goldleaf growing strong? Will that re-veg as well?

If you had to move to 12/12 to get it to flower, then I would leave at 12/12 for the duration. Some are probably stable enough that you could move back to longer schedule, but I would bet not all. Imo not worth risking plant herm or reveg.


Thanks @dbrn32 ! Does that mean the other 3 will be stunted?

1 Like

I guess depends on your definition of stunted? They are autos correct? They look fine, just small. If you have good enough light density you can hit recommended dli on 12 hour schedule, so length of light time isn’t critical from that perspective. They are flowering, so growth in terms of plant size is pretty much over. I would say this is inherent risk that is pretty much accepted when choosing to grow autos. To get large plants you typically need a system that produces rapid vegetative growth or hope they are like your gold leaf and don’t want to flower easily on the long schedule.

If you are simply wanting to ensure you have larger plants, try photos next time. That allows you to control veg time, and essentially get plants to the size you want them prior to flowering.


That’s s bummer because my first autos were MUCH bigger and I’ve seen far larger auto grows on forums. Thanks for the info - lesson learned!

1 Like

For sure. There are members here that grow them pretty big, but most are in soilless media utilizing high frequency feeding methods or some sort of passive hydroponic system like an autopot. All known to provide fairly rapid growth when compared to soil grow. Sometimes experience can help a bunch too, and others plants just flower early.