Pruning Hydrangeas: The Ultimate Guide
When fall begins to arrive, many turn to maintenance endeavors in the garden. Cleaning of the vegetable garden, dividing perennials and pruning back shrubs. But not all shrubs should be pruned this time of year. Hydrangeas, for example, are a staple in the southern garden but not all are alike. In fact, there are 3 main types of hydrangeas and each has different rules for pruning.
The big leaf hydrangea is the shade loving shrub with colorful balls of blooms, usually shades of blue or pink, that grandmothers and their grandmother have grown for generations. Most of these old varieties of hydrangeas bloom in spring on “old wood”, meaning stems and branches that were there on the shrub the previous year. Buds are formed on these branches quite soon after the current year’s blooms fade and dry, so prune after they bloom, typically in May or June.
Paniculata are newer cultivars of the genus hydrangea, also called “Pee Gee”. These shrubs prefer mostly sun and sport more cone shaped blossom clusters which show up in mid summer. They are not as particular about soil conditions as the big leaf hydrangeas and thus can withstand many different soil qualities and textures. Panicle hydrangeas typically bloom on “new wood”, which means the new growth produces buds and eventually blossoms. Pruning these hydrangeas are a bit easier due to this fact. They can be cut back in fall through early spring, many preferring to prune in December or January while dormant.
The third type of hydrangea to consider is the smooth hydrangea. This shrub blooms on new wood, but typically has very large, heavy mop-head flower clusters. These shrubs should be pruned in early spring before the new growth occurs. Pruning heavily, to one foot from the ground, is suggested to encourage shorter and more stout stems for the heavy blooms.
There are several other hydrangeas to consider. For example Oakleaf hydrangeas bloom on old wood and must be pruned when their flowers begin to fade. There are also climbing hydrangeas which may need to be trimmed from time to time to keep their unruly vines neat and tidy, which is best done in early spring.
If any of your hydrangeas have dead branches, they can be pruned out at any time. Cold snaps may also be an issue with hydrangeas that bloom on old wood, so keep any eye on the weather in early spring. If temps dip below the 30s, cover your shrubs with frost protection to ensure buds will stay intact.
Hydrangeas are one of the most confusing plants when it comes to knowing when to cut them back. Hopefully this information can help you have beautiful blooms for years to come!
