How To Prune Hydrangea

When and how to prune hydrangea is a source of concern to many home gardeners who worry they'll kill the plant. Here are some steps to follow to ensure proper hydrangea pruning.

Step 1: Determine Type Of Hydrangea

Different types of hydrangea have different pruning requirements. Determine which hydrangea variety is in the garden before attempting to prune.

Popular garden types are Bigleaf, Mophead and Lacecap. These flower in mid to late summer on shoots that grew the previous year. Types that flower on new growth include Oakleaf, Arborescens and Paniculata. Another type, the climbing hydrangea, is actually a vine, not a bush, and requires little to no pruning.

Step 2: Hydrangea Requiring Pruning After Blooming

Bigleaf, Mophead and Lacecap, since they bloom on the previous year’s growth, should be pruned after blooming when the plant goes dormant or all the leaves fall off.  Depending on climate zone, this is generally late fall. These types of hydrangea can also be pruned in the early spring before new growth begins and is the preferred time to prune if the area is subject to harsh winter temperatures.

The procedure involves pruning old flowerheads to the first pair of strong, healthy buds. More pruning can be done on mature, established hydrangea bushes to remove older stems and encourage new growth from the plant’s base.

Remove all dead canes by cutting them down to the ground. If the plant is more than 3 years old, thin out by removing a third of the oldest canes, again cutting to the ground. Remove any old flowerheads that remain. Remember that any green buds removed at this time could have been more flowers, so keep in mind whether the goal is more flowers or a neater plant.

Step 3: How To Prune Oakleaf, Paniculata And Arborescens Hydrangea

In order to ensure a new crop of sturdy stems, Oakleaf, Paniculata and Arborescens hydrangea should be pruned in early spring.

Prune stems back in February or March either to near ground level or even with the hydrangea’s main trunk. Sturdy stems are required to ensure masses of blooms at the ends of arching stems. In the fall and winter, do not trim or prune off the old flowerheads, as they will still look attractive throughout this time.

Step 4: How To Prune Pee Gee Hydrangea

Some gardeners like to train the Pee Gee hydrangea to become a small tree by removing a third of the plant’s lateral small branches from the ground up. This should be done in late winter or early spring. After these branches are pruned off, cut away any crossed branches or those that aren’t growing away from the middle of the plant.

Although Pee Gee hydrangeas can be cut to any size between 6 inches and 3 feet tall each year, it’s best to plant in a location where it’s free to grow large. Don’t prune hard to the ground. Gentle pruning keeps the plant healthy and encourages new growth.