There are several plants referred to as waxberry, this article deals with the edible fruit also known as 'Yangmei' in its native China. Its latin botanical name is 'Myrica rubra'. They are related to bayberries and some cultivars are called Chinese Bay Berry.
The tree that bears these tasty litlle tidbits is an evergreen that can reach over 60 ft in height, although most specimens are much smaller and can be trained and pruned to manageable heights.
Two trees are needed to produce fruit, both a male and female tree as they are dioecious, with separate male and female plants. On extremely rare occasions a tree with both male and female flowers occurs . Waxberries do best in moist humid subtropical regions. They have no really overly taxing soil requirements and are tolerant of poor quality acidic soils with a pH of 4 - 6.
Temperatures from slightly over 100 F to as low as 25 F are tolerable. Optimal temperatures around 65 - 70 F are best.
It requires a fairly high rainfall in its native regions and common sense dictates that it also needs ample watering in areas that can not meet this criteria. The period around fruit development, as with all fruits in particular needs to be kept well watered - more so than most standard native fruit and nut trees.
Fertilizer is not really much of an issue, it can survive in some pretty poor soils. Wax berry trees are also believed to function in a similar fashion to beans/Legumes as they will fix nitrogen in the soil via a slightly different mechanism - this however is not proven.
The Waxberry fruit is spherical deep red to purple with a pitted rough exterior. The exterior is somewhat similar to arbutus berry aka Strawberry Trees in appearance but not taste. The inside flesh is tart and succulent with a lighter reddish hue. The berries contain a large single seed in the center.
Fresh waxberries are difficult to locate in North America as they must be imported. It is currently prohibited to import these trees here as they come with non indigenous insects whose spread is not really welcome. Seeds however are available for the more adventurous botanist or gardener wishing to try their hand.
They have been promoted as a super-fruit as they have a high vitamin and mineral content. Thiamin, carotene, riboflavin, Vitamins C and E are all found in abundance with waxberry fruit. Although the berries rarely appear in North American Produce markets they can be found from time to time, particularly on the West Coast. A juice made from the berry is marketed as "yumberry juice" which is readily available.