Oak leaf hydrangea, known botanically as Hydrangea quercifolia, is a flowering shrub grown largely for its large and pretty foliage that turns red, rich yellow and burgundy in the fall. The flowers are white to pale pink or ivory and have more of an upright cone shape than other hydrangea cultivars. Quercifolia thrives in sites protected from heavy winds and in filtered sunlight or partial daily shade and uniformly moist soil. Pruning requirements are minimal and once-a-year light trimming and grooming is often sufficient in most climates.
Prune oak leaf hydrangea in the early spring before new growth appears, using the loppers and hand pruners. Place all cuts on the bias and roughly 1/8 to 1/4 inch above a leaf node or bud to encourage branching and new bushy growth.
Trim away any winter damaged, dead or diseased branches down to healthy wood or the crown of the plant as needed. Pull each severed branch from the canopy and discard.
Reduce the size of the shrub only when required to suit the setting by trimming back the terminal branch tips to the desired length. Never attempt to remove more than 1/3 of the overall bulk of the shrub in any single pruning session or shock may become a concern. Follow the natural rounded and spreading form of the shrub, trimming evenly for a roughly symmetrical overall result.