Oakleaf hydrangea (Hydrangea quercifolia) is a popular native shrub in the Southeastern U.S. (USDA hardiness zones 5 to 8). Two new compact forms of oakleaf hydrangea were recently introduced by the U.S. National Arboretum. In early summer, ‘Ruby Slippers’ is covered with 9-inch-long floral clusters that are held upright above the foliage. ‘Ruby Slippers’ grows […]