early sexing 12/12

[Herbiraptor]

I am in Southern hemisphere and it is time to start.

I have only very limited outdoor space, just for a few plants.

I have started some seeds and am going to put them under 12/12 from begining and as soon as they show sex put the females outdoors after hardening.

How long before plants will show sex in this way?

I am new to this idea so any suggestion will be helpful.

Thank you

 

[GroHi]

I had always been under the impression that you wanted to grow seeds out until the showed presex flowers before you actually flipped them... that would take you 5~7weeks from the time they hatch. ???

 

[l33t]

hi Herbiraptor

This is exactly how we grew this year outdoors. Started seeds under 12/12 from seed indoors and they all showed sex by day 18-23 from germination. Then when all were sexed we put em to 18/6 for a week and then took em outdoors where the lighting was similar (15/9).

I ve started seeds straight under 12/12 and most strains show sex from 14 (males) to day 25 for the slower ones. Some pure sats may be a little bit slower than that but the majority of hybrids will show sex within the first 3 weeks or so.

 

[scrapiron]

l33t, do they go back into veg pretty easily once they have been sexed? How long is the transition? It seems like I read there is a long period of almost no growth. ?

 

[Tobor the 8th Man]

Grow them until alternating leaves and see if they show sex. If not 12/12 them for 4 days and then back to 18-6. They will show preflowers and not have to do a full turn from flower to veg. They will veg almost as normal. The little 4 day burst of 12/12 pushes them to reveal sex.

Otherwise just look for preflowers until you put them outside. I know 12/12 from start has its uses but it will stunt them. They won't get as big as they would have normally and some can get freakishly stunted.

If you must 12/12 let the seedlings at least go 3 weeks or more before 12/12. Less chance of mutated runts.

I have always grown outdoors and normally don't 12/12 for sex. The one grower I have seen get monster plants outside and did 12/12 did the 3-4 days 12/12 method.

 

[Herbiraptor]

Thanks guys, good info.

 

[Jalisco Kid]

I would grow them 18/6 then take cuts and put the cuts under 12/12 for 2 weeks with a loupe you can sex them. Take your extras and find a creek bed to plant them. Come back in 6 months you might get lucky.JK