Suggest that you switch your sights to a berry plant that is evergreen. Try a huckleberry.

Agree with Charlie... if you're willing to expand into berries (and even nuts) that grow on shrubs, brambles, or groundcovers, you will find a few that are evergreen in your area.

-- Silverthorn, Elaeagnus ebbingei/pungens
-- Creeping Raspberry (a groundcover)
-- various species of cacti
-- pinyon pines
-- live oaks
-- Mexican elder

I forgot, among others:
-- strawberry tree (arbutus)
-- lingonberry
-- Chilean guava
-- cold hardy Citrus and hybrids (dare I say it?)

All of the plants I mentioned in this and the last post should be hardy or nearly so in zone 7, but may not like other aspects of your climate (I doubt there are many folks there growing most of them).

You can find any of these plants at one of the nurseries specializing in unusual fruiting plants, such as Raintree, Burnt Ridge, One Green World, Edible Landscaping, etc...

Evergreen huckleberry would take a long time to grow to 10 feet if planted in a shady spot. In sun stays smaller. Small crop, one to five pounds per mature plant.

Arbutus fruit is edible but pasty and not tasty. Some varieties are mildly sweet. Bigger crop than huckleberry, grows much faster.