My neighbors have two huge, beautiful gingko trees right by the sidewalk. One is male and one is female. Apparently this was a grand oversight by whoever planted them. Female gingko trees can only produce fruit after they're about 25 years old, and even then, only when they're near a male tree. That fruit then falls off the tree, and completely reeks when it's stepped on. It's seriously pungent. My advice to you: separation of the sexes for all gingko trees.