Hydrangeas: To Prune Or Not To Prune?
It’s a question we get asked all the time. Unfortunately, it’s a question that’s not easily answered. First of all, it’s very important to know what kind of hydrangea you have before pruning. If pruned at the wrong time, chances are they won’t bloom in the current or following season.
All hydrangeas can be put into one of four different categories: Mophead/lacecap, Oakleaf, Peegee, or Annabelle. Mopheads/lacecaps are usually the pink and blue varieties, and are the only ones that open with colored blossoms. They also have very short leaf stems (petioles) and hold the blooms close to the main stems. Oakleaf hydrangeas have a leaf similar to an oak tree and have white blossoms in a cone shape. Peegees are all white or cream when they open and often turn pink as they age. To be certain, look at the leaves. You’ll notice three leaves growing from one point on the stem and distributed in a whorl around the node. Annabelles (often called snowballs) have large blooms that open green, turn white and gradually turn green again. They also have long leaf stems that hold the blooms away from the main stems.
Once you determine the type of hydrangea you have, only then can you know how and when they should be pruned. Mophead/lacecaps and Oakleaf hydrangeas bloom on old wood. Old wood are stems that have been on the shrubs since the summer before the current season. Prune these types of hydrangeas in the summer before August to give them plenty of time to grow. This new growth will hold next year’s blooms. Peegees and Annabelles bloom on new wood, so these should be pruned in the fall or very early spring. All the new growth in the spring is what will form blooms later that same season. Remember, you can always prune dead stems or branches at any time.
In general, it’s always good to know what you’re pruning before you pick up your pruners.