when do males start flowering?

I have a question that I've been trying to find an anwser for, so I'm going to assume that other people have the same one. I'm wondering when outdoor male plants start to flower? I'm not talking about when they develop pods, or assert their sex, but when they actually begin to open and distribute pollen. I plan to sow an outdoor garden and then not look at it for approx. 2.5 - 3 months; about 1 month past the summer solstice. At that time I want to go in and remove all male plants. I'm running an experiment to see if it's possible to set up a wild grow that requires almost no tending except at specific times. I'm going to use a variety of different seeds for it, so to be honset, I'm really looking for dates that I need to start keeping an eye on. If anyone can tell me the earliest they've had males begin to flower that'd be awesome.:D

Depends on latitude.

Commercially, this is usually done w/ cuttings or fem seed.

Yup, I'm aware of this, but I wanna go a bit more naturalistic...think of it as a hobby for wasting downtime when I have it, rather then a commercial operation. As for latitude, I'm sitting about about 50 degrees north.