By pruning right after the blooms have faded, you allow the plant time to set buds for the next year. Oakleaf (H. quercifolia) and bigleaf hydrangea (H. macrophylla), including Nikko Blue and all the other pink- and blue-flowering cultivars, bloom from buds set the previous year.
Aug 05, Both smooth and panicle hydrangeas bloom on new wood. Cut smooth hydrangea 6 to 12 inches from the ground, or at half its height, every year in late winter or early spring. The height you choose to prune these hydrangeas is strictly personal preference.
Pruning after initial flowering can even stimulate a second flower takedownbush.buzzted Reading Time: 7 mins. Apr 25, Bigleaf hydrangeas (Hydrangea macrophylla cvs., USDA Hardiness Zones 6–9) Bigleaf hydrangeas (H. serrata cvs., Z 6–9) Oakleaf hydrangeas (H. quercifolia cvs., Z 5–9) Prune after the flowers start to fade in late summer.
To determine if your hydrangea blooms on old wood, think about when it takedownbush.buzzted Reading Time: 9 mins. May 10, For shrubs that bloom on old wood, prune off the flowers as soon as they start to fade in mid-summer and trim older stems at the base to promote new growth. If you have a shrub that blooms on new wood, cut back the stems by 1/3 in late winter and remove any dead canes%.
Prune these hydrangeas only in the summer before August (to be safe). Some experts believe these hydrangeas may be pruned even into August, but this might be risky.
The hydrangeas may already have set their bloom buds for the next year.