Deadheading is the practice of removing spent blossoms to improve a hydrangea shrub’s appearance and redirect the plant’s energy. While it may encourage reblooming, the main benefit is aesthetic, helping the plant focus on new growth rather than seed production. To promote future blooms, the location of the cut is crucial. Knowing precisely where to snip the old flower head ensures you do not accidentally remove the embryonic flower buds for the following season.
The Critical Distinction Between Hydrangea Types
Before deadheading, you must determine whether your plant blooms on “old wood” or “new wood.” This distinction dictates the correct cutting location and timing, directly impacting future flower production. “Old wood” refers to stems that matured the previous season, while “new wood” is the fresh growth produced in the current growing season.
Hydrangeas that bloom on old wood set their flower buds the previous late summer or fall, and these buds overwinter on the existing stems. Varieties like Bigleaf (Hydrangea macrophylla) and Oakleaf (Hydrangea quercifolia) fall into this category. Conversely, new wood bloomers produce buds on stems that grow in the current spring, making their pruning more forgiving. This group includes Smooth (Hydrangea arborescens) and Panicle (Hydrangea paniculata) hydrangeas.
Deadheading New Wood Bloomers
New wood bloomers, such as Smooth (‘Annabelle’) and Panicle (‘Limelight’) hydrangeas, develop flowers on growth produced in the current spring. Since the plant has not yet formed next year’s flower buds, deadheading is simpler and poses less risk to future bloom production. The primary goal is to tidy the plant’s appearance by removing the faded flower head.
The precise location for the cut is just above the first set of healthy leaves or buds below the spent flower. Using clean, sharp pruners, make the cut about one-quarter inch above the node. Cutting further down the stem is unnecessary for simple deadheading and should be reserved for heavier shaping or pruning done in late winter.
Deadheading Old Wood Bloomers
For hydrangeas that bloom on old wood, the flower buds for the next season are already present on the stem just below the current year’s blossom. Varieties like Bigleaf (mophead and lacecap types) and Oakleaf hydrangeas require a precise cut to preserve these developing buds. Deadheading is best performed immediately after the current flowers fade in early to mid-summer, allowing the plant time to set new buds for the next year.
The correct cutting location is immediately above the first pair of large, healthy leaves situated directly beneath the faded flower head. Trace the stem down from the spent bloom to find the small node where the leaves attach to the stem. The new flower bud is housed in the axil of this leaf pair.
Make the cut about one-quarter inch above this node, taking care not to nick the leaves or the embryonic bud. Cutting the stem too far down, past the first healthy node, will remove the pre-formed bloom bud, resulting in a lack of flowers the following year. Avoid performing any heavy pruning after late summer, as the plant needs this time to finalize the formation of next season’s dormant flower buds.