You won't generally see pre-flowers until you get to at least the 6th internode. So that's at least 6 proper sets of leaf's. You are probably talking 3 weeks to a month to get to that stage.

You can flower from seedling by putting the lights straight onto 12/12 but the plant will only actually start to flower once it gets to a particular level of maturity. So even though you put the lights on 12/12 the plant won't flower until its mature enough which again is going to be at least 3 weeks to a month.
glaeken Reviewed by glaeken on . Anyone know whats the earliest you can see sex? Got a little one going really well now under 2 x 20w energy savers and one 18w reptile flour(simulates daylight), I know what to look for and i think i can see tiny (and i mean tiny) little hairs coming from the pit. Its only got 6 propre leaves (plus the next 2 sprouting nicely) oh yeah plus 2 at bottom which only have one prong so 8 in total, is this way to early to get excited? Rating: 5