This is about che--- the fruit tree Cudrania tricuspidata, not the mixed-success revolutionary. It's related to the mulberry, close enough that in China its leaves serve as a backup food for the silkworm when mulberry leaves are scarce. The sweet, round fruit is mulberry-like in form, but reported to taste quite different, with a delicious watermelon-like flavor.
No freeze tolerance worries with che--- it can handle winter temperatures below zero degrees Fahrenheit. Two traits limiting its appeal have been the three to six small seeds in each fruit, and the fact that the small, shrubby trees are dioecious--- both a male and a female are required. Now, however, there is a seedless, self-fertile variety available.
Seedling trees take up to 10 years to fruit, but che is readily grafted onto another mulberry relative, the osage orange, which also prevents suckering and produces a tree form, rather than the natural shrubby habit.
It wasn't until I looked up some images that I recognized the osage orange as a familiar tree from my youth in Ohio. This picture of its fruit by Gale French is in the Wikimedia Commons. Though its fruit is inedible, the osage orange is an interesting tree worth an article of its own. The seeds are edible, though said to be difficult to obtain, and the dense wood has the highest BTU content of any North American fuel wood.
This spring I obtained my seedless, self-fertile che from master grafter Wayne Clifton. It's joined my three persimmon trees in a sunny area, not irrigated but well-mulched. If the fruit is a tasty as I expect, the che's small size, hardiness and beautiful foliage make it an attractive edible landscaping choice.