Pruning hydrangeas in October is one of the most common mistakes gardeners make in autumn, and it can cost you next year's flowers. According to gardening expert and co-founder of Savy Gardening, Jessica Walliser, there is "no need to do any pruning" as part of hydrangea autumn care, regardless of the variety.
Why Autumn Pruning Harms Hydrangeas
Walliser warned that cutting back hydrangeas in autumn could remove the flower buds that would bloom the following year. "Pruning in the autumn could remove flower buds for next year, depending on which variety of hydrangea you're growing," she said. "Pruning at the wrong time can result in reduced blooms or even no blooms at all."
Many gardeners mistakenly cut off stems they believe are dead, but this can lead to "a plant that's more prone to winter injury and produces fewer blooms." The expert added, "You could even be pruning off next year's dormant flower buds. In short, do not prune hydrangeas in the autumn."
Deadheading Is Optional
While deadheading—cutting off old blooms—is a possible autumn task for hydrangeas, Walliser explained that "it is not an essential one." She noted that removing dead flowers is "really a matter of personal choice" and will not affect the quality or size of next season's blooms.
Walliser also pointed out that most dead hydrangea flowers naturally fall off by spring, so she personally skips the effort. If you do choose to deadhead, use sharp pruning secateurs to trim just the flower heads, removing only an inch or two of stem. "Do not cut the stems back any further than that, or you could impact next year's flower production," she urged.
