To prune a hydrangea bush, sanitize bypass pruners, remove dead flowers and broken canes, shape the bush, cut back crossing canes, and remove a third of the oldest canes. The supplies you need for this one-hour procedure are bypass pruners, a bucket, bleach and water.Continue Reading
Fill a bucket with 1 part chlorine bleach and 9 parts water. Submerge the blades of your bypass pruners in the solution. Remove them, and put the bucket next to the hydrangea bush.
Use the bypass pruners to remove all dead flowers and broken canes. Cut off all diseased portions of the bush, and dip the pruners in the bleach solution after each cut. This prevents transferring the disease to healthy parts of the bush.
Enhance the shape of the hydrangea bush by cutting back scraggly and overgrown canes.
Search the interior of the bush for crossing canes, and cut back the older cane in each pair. It is also prudent to prune or remove inward-growing canes.
Remove one third of the oldest, woodiest canes, starting from the bottom of the bush. If the hydrangea is very young, skip this step.