I understand considering edibles for the permaculture landscape but I also like to include herbals and medicinals.
I'm not as familiar with what will grow in your zone but here, I will be planting Vitex trees which will serve to feed the birds as well as be used for medicinal applications.
Another small native tree that provides light shade and can be used medicinally is the Prickly Ash Hercules Club aka toothache tree. The bark can be peeled and applied for its' numbing effect orally.
