The sight of woody, seemingly lifeless stems on your hydrangea after a long winter is a normal result of dormancy or winter dieback. These old stems, often brittle and gray, must be removed to improve the plant’s appearance and health. Successfully removing this dead material requires knowing how to confirm a stem is truly dead and understanding the optimal timing, which varies significantly depending on the specific type of hydrangea you are growing. This guide provides the method for safely eliminating unwanted old growth without accidentally cutting off the buds that will produce summer flowers.
Diagnosing Deadwood Versus Dormant Buds
Determining whether a stem is truly dead or just dormant is the first step before making any cuts. Dormant stems are alive and contain the tissue needed for new growth, while dead stems are brittle and can potentially harbor disease. The most reliable way to differentiate between the two is by waiting until the plant begins to actively leaf out in the spring, making the dead material visually obvious.
A simple physical check called the “scratch test” can confirm the stem’s viability. Gently scrape the outermost layer of bark using a fingernail or small knife. If you see bright green tissue directly beneath the bark, the stem is alive and dormant, and should not be removed.
If the scratch reveals only brown, dry, or brittle material, that specific section of the stem is dead and can be safely removed. Since winter damage often affects only the tips of the branches, repeat the scratch test lower down the stem until healthy green tissue is found. Stems that are completely brown or gray and snap easily when gently bent are confirmed deadwood.
Determining the Optimal Time for Pruning
The correct time to remove the dead sticks is entirely dependent on whether your hydrangea blooms on “new wood” or “old wood.” This distinction dictates when the plant develops its flower buds and, consequently, when pruning can be done without sacrificing blooms. For all types, the diagnosis and removal of dead sticks should happen in the spring, only after the plant has started showing new signs of life, such as leaf emergence.
New Wood Bloomers
Hydrangeas that bloom on new wood, such as Hydrangea paniculata (Panicle Hydrangeas) and Hydrangea arborescens (Smooth Hydrangeas), form their flower buds on the growth produced during the current spring. Since the flowers do not exist on the plant over winter, these types are the most forgiving when pruning. You can safely remove dead sticks and perform shaping cuts in late winter or early spring before new growth emerges.
It is still best to confirm the dead status of a stem in the spring once the plant is actively leafing out. Removing all dead and weak stems back to the ground or a strong bud in early spring encourages vigorous new growth that will support the season’s blooms.
Old Wood Bloomers
Varieties that bloom on old wood, including Hydrangea macrophylla (Bigleaf Hydrangeas) and Hydrangea quercifolia (Oakleaf Hydrangeas), set their flower buds on the previous season’s growth. These buds overwinter on the stems, and cutting them off in late winter or early spring will eliminate that year’s flowers. Therefore, the removal of dead sticks must be done with caution.
The safest time to remove dead material is in the spring, after new leaves have emerged and you can clearly see which stems failed to leaf out. Cut only the branches confirmed as dead via the scratch test or complete absence of new growth. Pruning any live wood on these varieties should be limited to immediately after they finish flowering in the summer to avoid removing the following year’s buds.
Reblooming Varieties
Reblooming hydrangeas, like those in the Endless Summer series, produce flowers on both old wood and the new wood of the current season. While they offer a second chance at blooms if the old wood is damaged, the rule for removing dead sticks remains conservative. You should still wait until spring leaf-out to accurately diagnose the dead stems and cut them back to healthy tissue only, following the same careful approach as with old wood bloomers.
Step-by-Step Technique for Removing Old Growth
Once the dead sticks are identified and the time is right in the spring, use clean, sharp tools for cutting. Use hand pruners for stems up to a half-inch thick and loppers for thicker wood to ensure a clean cut that heals quickly. Clean tools minimize the risk of introducing disease to the healthy parts of the plant.
For a stem confirmed as completely dead, cut it back as close to the ground as possible without damaging the crown of the plant. Removing the entire dead cane allows more light and air to reach the center of the shrub, promoting fresh growth from the base.
If the stem is only partially dead, cut it back to the first set of healthy, plump buds or the first visible new leaves. Make the cut approximately one-quarter inch above this viable point. Cutting at a slight angle away from the bud can help shed water and reduce the chance of rot at the cut site.