bigleaf Hydrangea macrophylla USDA Zones 5-9. Blooms on old wood; rebloomers also flower on new wood. Do not prune. Protect in winter in the north. Proven Winners varieties: CITYLINE® series, LET’S DANCE® series PANICLE Hydrangea paniculata USDA Zones 3-8. Blooms on new wood. Prune in early spring. Proven Winners varieties: BOBO®, FIRE LIGHT®, ‘Limelight’, LITTLE LIME®, PINKY WINKY®, QUICK FIRE®, Little QUICK FIRE®, ZINFIN DOLL® smooth Hydrangea arborescens USDA Zones 3-9. Blooms on new wood; some are rebloomers. Prune in early spring. Proven Winners varieties: INCREDIBALL® series, INVINCIBELLE® series MOUNT AIN Hydrangea serrata USDA Zone 5-9. Blooms on old wood; rebloomers also flower on new wood. Do not prune. Proven Winners varieties: TUFF STUFF™ series OAKLEAF Hydrangea quercifolia USDA Zones 5-9. Blooms on old wood. Do not prune. Protect in winter in the north. Proven Winners varieties: GATSBY® series LET’S DANCE® RAVE® Hydrangea macrophylla BOBO® Hydrangea paniculata INVINCIBELLE® Spirit II Hydrangea arborescens TUFF STUFF™ Hydrangea serrata GATSBY PINK® Hydrangea quercifolia