Perennial plants return year after year with little maintenance. Much of our current gardening and farming practices use annual plants, which are often much higher in maintenance since they need to be replanted each year. Trees and shrubs containing nuts, berries, and currants make excellent edible landscaping.
Berries that grow well in Iowa include blueberries, lingonberries, juneberries, chokeberries, elderberries, and gooseberries.
These publications will help you understand how to keep your perennial fruit and nut plants thriving.
Arbor Day - Agroforestry Nuts and Fruits
Arbor Day - Edible Woody Landscapes
Arbor Day - Hybrid Hazelnuts
Growing Currants, Gooseberries, and Elderberries in Wisconsin
Fruits and Nuts for Edible Landscaping (excellent list of harvestig times)
Planting Woody Ornamentals - PB1612