Hydrangea arborescens – Smooth Hydrangea
The longer we grow hydrangeas the more impressed we are with our native wild hydrangeas, the arborescens. They were the first hydrangeas to be given a place in European gardens. The wild woodland form is a lacecap with wide, flat heads of creamy-white fertile flowers and very few or no sterile white flowers along the edge of the inflorescence. The discovery of mostly sterile forms of H. arborescens such as ‘Grandiflora’ and ‘Annabelle’, with their rounded heads of clustered white flowers, brought our wild hydrangea to popularity. Blooms emerge a soft pale green, become white, and age first to green, then to a tawny parchment brown. Our resilient natives carry on through the winter, making these a lovely choice for a woodland setting.
BLOOM SEASON June, with peak usually mid-June.
PRUNING Prune at the end of winter or beginning of spring. Since Arborescens bloom on new wood, it is possible to cut them back to about 1' above the ground. This produces large blooms that tend to bow the heavily-headed stems, particularly when it rains. Lighter pruning results in numerous smaller blooms on a tidier shrub and in our opinion a lovelier plant. In areas with long growing seasons a second flush of bloom is possible by removing spent flowers and gently shaping the plant. Make cuts above a node (a joint on the stem).
CULTURAL INFORMATION The arborescens prefer rich, moist, well-draining soil and partial shade. Although they demand consistent watering, they will not tolerate poor drainage. Be sure not to plant too deeply. Where happy, the 3' – 5' wild hydrangeas will spread by suckering. Hydrangea arborescens has a native range extending from the Midwest to New York and all across the southeast indicating its excellence as an addition to almost any garden. In colder climates, more exposure to sunlight is desirable. Zones 4 to 8.