Sprouting Seeds Under 12/12 Lighting to Determine Sex and Re-Vegging the Females... Is It Bad??

A reputable Instagram grower I follow says he pops his seeds under 12/12 lighting to determine sex. And as soon as they show their gender he takes the females to his veg room while the males get culled. The females go through re-veg this way right? Is this technique bad for the resultant mother plant at all? Or will she resume vegging as normal?

I currently have 13 seedlings growing at the moment that are at about two weeks old. I was going to let them grow about three or four nodes high and then i was going to take a cutting and throw the cuttings in a cup of water under 12/12 lighting to determine sex. But now I'm having second thoughts...

The sprout from seed under 12/12 method actually seems more efficient and convenient than taking a cutting and putting the cutting under 12/12 lighting. Can I re-veg seedlings rest assured that the mother plant will behave as normal once she gets out her funk and is in veg again? TIA!

I do and currently am. All my ladies have just shown some pistils over night (literally since yesterday) and they'll be going outdoors, soon.

It's called sexing

[Add] They weren't from 12/12 as I let them grow for 2 weeks then stuck them into the flower tent.

Take note that they can/do and will get a little stressed out when reverting back to veg, growing leaves as if they were clones but then back to normal.

bigbillyrocka said:

[Add] They weren't from 12/12 as I let them grow for 2 weeks then stuck them into the flower tent.

Take note that they can/do and will get a little stressed out when reverting back to veg, growing leaves as if they were clones but then back to normal.

Click to expand...

so once they get through that stress phase they will resume vegging normal and be perfectly healthy assuming environmental conditions are good?

will the structure be any different at all? I'll still be able to top the way i like to top, LST and do my flat canopy SCROG?

[Add] do you think a 2-foot tall tent is tall enough to sex them before returning them to my veg room? im gonna order one right now if so

newguy41410 said:

so once they get through that stress phase they will resume vegging normal and be perfectly healthy assuming environmental conditions are good?

will the structure be any different at all? I'll still be able to top the way i like to top, LST and do my flat canopy SCROG?

Click to expand...

Sorry I didn't reply in time.

Once they get through that little phase you can resume what you would normally do and see little to no difference, whatsoever.

It's a great way to know what you'll have

newguy41410 said:

[Add] do you think a 2-foot tall tent is tall enough to sex them before returning them to my veg room? im gonna order one right now if so

Click to expand...

I would say yes but with some caution:

Currently, my little ones are in 1 gallon pots. I flipped them from veg to 12/12 when they were about 8 inches and all but one are now 18 inches with the tallest one (Dutch Treat) at about 28 inches.

The 1 gallon pots are about 7-8" tall.

Had I topped these ladies, i would have had plenty of space to fit under 2 feet but would need something larger- sooner.

Of course, you can always sex in smaller containers but with added stresses when up-potting.

If you catch them early enough.Spot the male or female preflowers...they will not go thru a reveg process.That's IF you spot the pistillate stigma or the "sacs"soon enough.Let her start budset and you'll have to go thru the reveg funky 1 blade leaf stage before returning to normal vegetative growth.
If won't effect how you want to train your plant,lst,topping etc.
Flower from seed I usually see sex around the 18 -21 day mark.During stretch.
I do flower under 10/14 so I'm not sure if that has any effect on how soon they show sex.

From my understanding a seedling won't flower or be mature enough to show sex for 2 weeks regardless of the light schedule.


So I've always vegged out normally for the first 2 weeks before I flipped the light schedule.

A clone would be different, I'd assume it would flower just as quickly as the mother since it would be just as mature.

Cannabis growers agree that stress is to be avoided, and yet one subject that point is disregarded is the light flip to 12/12. And the stress going from 12 to more hours to re-veg.
You can do it with confidence that the plants will fully recover.
But I prefer (don’t always do it) to phase my flip in 30 minute increments. It makes sense that they suffer less stress with this method, but I can’t prove it.

2’ tall tent”. Crazy close light to plants!

First time hearing about this sexing method... makes sense and a time saver! Thanks for sharing! Everyday is a learning experience on RIU... I may be developing a habit lol