gender question

I have some seeds of critical mass i just started growing. they are not feminized though, they didnt have any for sale. so anyways i got 18 of them and hoping 12 are female. can i keep all 18 together to veg big enough to put a bag over a branch to force flowering early to see which gender it is? or do they reproduce in vegetation? thanks a lot for the help.

Hey their!
First off, welcome to RIU!
Theirs alot of threads you can find with all the info instead of putting up single questions.
Heres a site with other info,
http://www.weedsthatplease.com/flowering.htm

Read that,
VERY informative!

you can keep them all together as long as you have room under your lights. good luck on getting that many females. My last grow from regular seeds yielded 4 females out of 14 plants... Overall average should be 50/50.

let them grow for 3 weeks, then put them under 12 of dark/ 12 hours light schedule. they will show sex after 2 more weeks. then you can get rid of the males.