American Persimmons flower early (May and June) and the flowers are unobtrusive. Honestly I've never seen/noticed any flowers except for the one time I went looking at the right time of year. Partly this is because the flowers aren't brightly colored and I don't have great color vision, though; your mileage may vary.
I know of some mature trees growing in shaded understory that have a nice umbrella shape and make lots of good fruit that's all within my (tall person) reach. Which is to say, the trees can't be more than ten feet tall, tops.
I don't have any sense of how long it takes persimmon seedlings to start making fruit. I have half a dozen that I've planted over the last eight years that haven't done it yet. But they all could be males! I won't know until I actually get flowsers/fruit.
All of mine so far have been stunted slow growers that are, at most, six feet tall right now. My guess is that they don't make fruit until they reach a certain degree of establishment; whether this is age-related or has more to do with conditions and weather I don't know. All I can suggest is to baby them. A thick layer of
mulch and lots of
water during droughts is my best advice; these are a wetlands/riparian species where I am and seem much happier with damp
roots than with dry ones.
I do have one tree that's a
volunteer near the edge of my orchard area. That space was leased pasture until about 2005. Fallow since then, it's now a dense regrowth forest. The tree in question is as thick as my wrist, growing straight as an arrow, and climbing like mad in competition with the rest of the forest for light. It's almost thirty feet tall with the lowest branches out of my reach. Still no idea if it's male or female. But if it's male, it's going to make an exquisitely fine piece of ebonywood timber for somebody after I am dead.