Red Empress™ Goji is one of the most popular varieties grown commercially. They produce good crops of large, dark red, sweet and flavorful berries. It is best to grow goji against a wall or somewhere it can be tied up as they tend to sprawl, growing 6-8 feet in height. They are self-fertile and like full-to-half-day sun and well-drained soil. Hardy to -15° and not bothered by pests or diseases. This sweet, tasty berry is very healthful and ready for harvest in late summer through fall. USDA Zone: 5.