Also known as Chaste Tree, Vitex has aromatic green leaves and stunning long, narrow spikes of purple flowers that cover this plant in the summer months. These fragrant flowers attract bees, butterflies and hummingbirds. After blooming, narrow spikes of round, dark brown seeds are produced. Vitex grows shrub-like, but can be shaped into a tree form by trimming away the lower branches during its winter dormant period. They can achieve a mature size of 25 feet tall and wide. Handles hot summers, as well as tolerating short-term temperatures below Zero F. Hardy in Zones 6-10.