Hydrangeas are a highly favored plant across Virginia, adding substantial color and texture to the landscape throughout the summer months. These flowering shrubs thrive in the state’s climate, which typically encompasses USDA Hardiness Zones 6 through 8. Successful and abundant flowering, however, depends almost entirely on the gardener’s understanding of when to prune the plant. Pruning timing is a delicate matter because incorrect cuts can easily remove the buds that would otherwise produce next year’s blooms. The proper guidance is tailored specifically to the Virginia growing season and the distinct characteristics of each hydrangea species.
Identifying Your Hydrangea Type
Determining the specific type of hydrangea you have is the first step toward effective pruning. The various species fall into two main categories based on where they set their flower buds: “Old Wood” bloomers and “New Wood” bloomers. Old Wood types, such as the popular Bigleaf (Hydrangea macrophylla) and Oakleaf (Hydrangea quercifolia), form their flower buds on the stems that grew during the previous summer and fall. These buds must survive the Virginia winter to produce flowers the following season.
New Wood bloomers, which include Panicle (Hydrangea paniculata) and Smooth (Hydrangea arborescens) varieties, form their flower buds on the current season’s growth. This difference is significant because it means New Wood varieties can be pruned aggressively without fear of sacrificing the year’s flowers. If you do not have the plant tag, look closely at the stems in the fall or winter to identify your plant type. Old wood stems are generally thicker, tougher, and may have a gray or brown color, often revealing visible buds already formed at the tips. New wood stems are typically softer, more flexible, and retain a slight green tinge with no visible buds in the dormant season.
Pruning Timing for Old Wood Bloomers
For Old Wood blooming hydrangeas, the correct time for pruning in Virginia is immediately after the flowers have faded. This usually occurs in mid-to-late summer, around July or early August. Pruning during this narrow window allows the plant enough time to develop new growth and set next year’s flower buds before the autumn arrives. Any structural cuts made after August risk removing these newly formed flower buds, resulting in few or no blooms the following summer.
Pruning on these types should be minimal and focused primarily on maintenance rather than size reduction. Gardeners should remove dead, weak, or non-productive stems by cutting them back to the base of the plant. If the shrub needs to be reduced in size, remove only one-third of the oldest stems, cutting them down to the ground to encourage rejuvenation. Deadheading, the removal of only the spent flower heads, can be performed to improve the plant’s appearance and direct energy toward bud production.
Pruning Timing for New Wood Bloomers
New Wood blooming hydrangeas, which include varieties like ‘Annabelle’ and ‘Limelight,’ should be pruned during the late winter or early spring dormancy period. In Virginia, this typically means targeting the months of February or March, before the plant breaks dormancy and rapid new growth begins. Pruning at this time is effective because the plant will produce its flower buds on the fresh stems that emerge in the spring.
Gardeners have much more flexibility with these types and can prune them back aggressively to maintain a desired size and shape. Since the flowers are borne on the current season’s growth, cutting the entire plant back significantly, sometimes even to within a foot of the ground, will not impact the summer bloom. This heavy pruning is often beneficial because it encourages the growth of strong, sturdy new stems capable of supporting the weight of the large flower heads. Delaying this pruning until after the spring growth starts can weaken the plant and reduce the overall vigor of the new stems.
Technique and Avoiding Common Pruning Errors
Regardless of the hydrangea type, pruning requires the use of clean, sharp tools to ensure a healthy cut. When making a cut on any stem, always locate a healthy bud or a set of leaves and make the cut just above that node. This practice directs the plant’s energy to the remaining bud, promoting growth in the desired direction. Throughout the year, gardeners should prioritize the removal of any branches that are dead, diseased, or crossing and rubbing against other stems.
The most frequent pruning error is misidentifying the plant and pruning an Old Wood bloomer in the spring. This mistake removes all the flower buds that survived the winter, resulting in a season without blooms. Another error is performing severe cutting on Old Wood types for size reduction when a light, thinning approach is warranted. Always remember that heavy pruning is reserved for New Wood varieties, while Old Wood varieties only require the removal of older canes for rejuvenation.