has any one determined plant sex by covering 1 branch with black poly??

2try here. has any one determined plant sex by putting 1 branch into flower by covering with black poly(twist tie)for 12/12?I've seen it mentioned in several how twos.but I would like to here from some one who's done it.I start my seeds under flourescents for 2 weeks.I then have a 2nd story deck were I harden them off.after there out there a few weeks.it would be nice to weed out the males. before I hump all the soil dig the holes watere them ect.ect.ect.75 people looked at my 1st post.if its bullshit that's fine.I would just like some feedback. Thanks

yeah, you can, I tried, but didnt have black poly, used aluminum foil, ended up just killing the branches haha.

Gotta be careful with the branches and I noticed early on it was a BITCH to remove and put back on the cover.

I've read about people doing that before, but it sounds like a lot of work as far as having to cover and uncover the damned thing every day. You could take a cutting from the plant, get it to root and put that into a 12/12. Then if it's female, you have TWO females!