Your cocoa plant will begin fruiting when it is roughly 5 to 6 years old. Although each cocoa tree has both male and female flower parts, they are not generally self-fertile, and need to be pollinated by another tree. In nature, this is done by small insects, but if you grow your cocoa trees indoors, you can often help the process along by rubbing the pollen from one tree on the female part of a flower from another tree.