Hydrangea radiata

Until recently, Hydrangea radiata was considered a subscpecies of Hydrangea arborescens, and they are very similar. Both are fast-growing and short-lived woody shrubs 3-6 feet high and wide. Both present a rounded form, with many, scarcely branched, twisting stems, shreddy bark, and white, flat-topped floral assemblages called corymbs, 3-6 inches across, of both sterile and fertile florets. Unlike “mophead” Hydrangeas which have only the open, sterile, petaled flowers, both of these species support a wide range of pollinator insects. Both grow well in part shade, in medium-moisture, organic, well drained, acid soil conditions. They are often treated like herbaceous perennials in the garden because, since they set flower buds on new, woody growth each year, they profit from semi-hard pruning sometime before spring, similar to a perennial. Against these similarities with H. arborescens, H. radiata stands out because of the bright white/silver underside of its leaves, which show up whenever a breeze blows, and because its flowers have more of the open, petaled florets on the perimeter of the corymb, making a showier show! Whereas H. arborescens is found in forests and roadside seeps from southern New York to the panhandle of Florida, and west to eastern Oklahoma and southeastern Kansas, H. radiata is found in a relatively small area near the junction of western North Carolina, South Carolina, Tennessee and Georgia. This plant is much loved for sparking up the shady edge of the woods with its elegant white flowers at a time in the summer when not much there is flowering. Unlike some of their Asian cousins, the color of these Hydrangeas is not affected by pH or the presence of Aluminum in the soil but is reliably sparkly white.