If you are growing your hydrangeas in pots, pruning those hydrangeas is easy once you know the type of hydrangea you are growing. Different types require pruning at different times of the year though in all cases the steps you follow are the same.

Steps:

• Start by taking your sharpest set of gardening secateurs.
• Sterilize your gardening secatuers so that you do not transfer any bacteria, fungus, mold, or anything else from one plant to another.
• Cut back the stems without damaging the remaining stems, leaves, or root structure.

Figuring out when to prune is based upon when your hydrangea blooms because the overall goal of pruning is to do it before new blooms start to develop that way you don’t damage the potential flower growth you would receive the following year. The biggest mistake most people make it cutting back to late which removes next years flower buds.

When to prune

When to prune your potted hydrangea is based on the variety.  

Late summer bloomer

If you have a hydrangea that blooms in the late summer it is important to prune the hydrangea in the early spring or the late winter before any active growth is initiated. These varieties include the Annabelle, PeeGee, Burgundy Lace, Limelight, and Quickfire.

The botanical names are the paniculata and the arborescens.

Blue or summer bloomer

If the hydrangea is a blue hydrangea or it blooms in the summer then you should prune it after it is finished blooming. Most of these hydrangea varieties produce blooms on old wood, the wood from last season. So if you decide to prune in the springtime you might cut off the dormant buds. By pruning immediately after all of your blooms have faded you will give your plant time to create the buds for the following year. The varieties include Nikko Blue, Blushing Bride, and Endless Summer.

The botanical names include quercifolia (or oakleaf), and marcophylla (or bigleaf).

Below is a chart to make it simpler:

Common Names	Botanical Name	When to prune
Panicle hydrangea	Hydrangea paniculata	Late winter
Bigleaf, mophead, lacecap hydrangea	Hydrangea macrophylla	After blooms in summer
Mountain hydrangea	Hydrangea serrata	After blooms in summer
Smooth hydrangea, Annabelle, Snowball	Hydrangea arborescens	Late winter
Oakleaf hydrangea	Hydrangea quercifolia	After blooms in summer
Climbing hydrangea	Hydrangea anomala	After blooms in summer

Deadheading

Deadheading is the process of removing dead flowers from the plants. This is much easier to do with potted hydrangeas and it allows you to keep a much more groomed and aesthetically appealing appearance for the plant. However, many people confuse this with pruning and think of it as the same thing. That said, the steps involved are the same. You’re going to follow the same steps as listed above but the difference is you’re simply going to remove the dead flowers rather than cut back whole stems or branches.