Female Seeds. How is this possible?

Hello everyone.

I have seen 'female seeds' advertised, and was wondering how it is possible to know a seed will grow into male or female?

Is it possible? How?

Theres more then one way to create a femenized seed. but as i understand it, a small % may still be male. one way is a chemical poisening. one way is selective breeding. sorry i cant help more. there's bound to be info on the web. i read on it before. there some info in the growFAQs too.