Flowers arise in leaf axils and may be either hermaphroditic (possessing male and female plant parts) or male.
Some trees may produce only male flowers. Graft on a scion off a female.
Male flowers are usually in clusters of 3 to 7.
Female flowers are usually solitary. Flowers are white and tubular, with a green calyx and an 8 to 12 carpel ovary.
Black Sapote apparently can have female flowers, male flowers, and hermaphroditic flowers. Some trees may remain only one sex and not have any fruit unless pollinated by another plant and others can one day produce flowers to have pollination.
They often take a while to produce female flowers. Seedlings often produce only male flowers, which are narrower and the flower quite triangular, for the first few years of flowering. The female flowers are much rounder and more tubular. Some seedlings never produce female flowers. Grafted plants should set fruit within 2-3years. (Bruce)
Grafting Black Sapotes I kept hearing that they are hard to graft so went looking for answers. One big production nursery uses cleft grafts on very juvenile seedlings. Another nursery uses side veneer grafts on a little larger material. Both leave half a leaf at the tip of the scion and bag. Both nurseries say it is an easy graft.