Pruning Guide for Hydrangeas:

1. Hydrangea macrophylla or bigleaf hydrangeas should be pruned right after they finish blooming. Cut back at least four to eight inches below the old bloom heads. They include ‘Nikko Blue’, ‘All Summer Beauty, ‘Blue Wave’, ‘Variegata’, Dooley. Emile Mouillere, Lady in Red, Masja, Mini Penny, and Penny Mac.
   
2. Hydrangea paniculata or panicle hydrangeas bloom on new wood so they can be pruned in winter or early spring. They can be cut back heavy. The most common varieties are ‘Pee Gee’, ‘Tardiva’, Vanilla Strawberry and Limelight
3. Hydrangea quercifolia or oakleaf hydrangeas should be pruned right after they finish blooming. ‘Pee Wee’, ‘Alice’, Amethyst and ‘Snow Queen’ are examples of oakleaf hydrangeas.
4. Hydrangea arborescens or the Smooth leaf hydrangeas bloom on new wood. You can literally cut them back to the ground each year and they will bloom with intense vigor. These plants tend to droop really bad in hot weather so giving them a hard cut helps to get them through the summer. ‘Annabelle’ is an example of arborescens.
5. Hydrangea anomala sub. Petiolaris or climbing hydrangeas should have approx. half their runners cut back at least every third year.