Goji berries are a surprisingly tough and adaptable shrub for Montana’s cold climate. Once established, they tolerate drought, heat, and extreme cold while producing nutrient-dense red berries packed with antioxidants. In past years, we offered cultivated varieties of Goji, such as Phoenix Tears, although we did not notice that the berries were much better or larger (Spoiler: they all taste disgusting fresh and must be dried). Once the berries are dried, they're quite good.
In our experience, they grow best in full sun and well-drained soil, and can survive -40F or possibly colder.