Pollin Question

1st grow here, a dozen plants outdoor w/ little care getting about 15 hours light/9 hours of dark. From researching I don't think I can definitely tell gender until flowering begins..but at what point can males contaminate females?? Before flowering? Or am I safe until then?
I'm sure it has been asked but I couldn't seem to find it.
Thanks

They cant pollenate until the balls appear....in a nutshell...they dont have the tools for the job until they go into flower

that's what I thought/hoped. So I'm fine leaving all the plants together until I can definitely tell the gender, correcto?
Thanks

Yup, correct If you see any balls - get the plant(s) out of the way unless you want seeds on your females. If all plants were planted at the same time then you should be able to tell the males before they show sex signs. Males tend to shoot up and grow really quickly as they mature quicker than the females. So keep an extra eye on any plants that suddenly shoot up fast