Hydrangea arborescens 'Annabelle' is one of those outstanding cultivars that outdoes others in this group. It features a much larger flower than the species, sometimes 1 foot across. Wow! Picture a plant in your yard 5-6 feet tall and wide covered with these 'basketball' sized white flowers all summer. It will 'knock your socks off!'. The species Hydrangea arborescens, commonly known as the smooth hydrangea is native to southern Missouri, growing in moist ravines or along streambanks. The flowering is typically in summer, June - August, but may continue through September in some areas.