Coffee is restricted in its growing range. The tree, Coffee arabica, the arabica coffee from Ethiopia, is frost tender and appreciates shelter and regular water over the growing season. Young trees also seem to like some shade from overhead trees although my plant which is fruiting is growing in the direct sun and seem to be happy. Over the winter time they can get quite stressed because of cold, wet conditions. They can grow up to 6 metres.
The beans are flavourless until they are roasted which is the skilled part of producing a good brew. Coffee from Coffee arabica has a milder flavour and less caffeine than that from Coffee canephora the robusta coffee which comes from the Congo.
Commercially, milder coffee comes from lowland plantations and stronger from highland ones. Whether this is due to temperature or not I do not know. NZ has a close relative in the form of Coprosma and early settlers used its berries as a form of coffee.