Thanks for writing. Any of the Hydrangea paniculata varieties, such as 'Limelight', 'White Diamonds', 'Pink Diamonds', 'Little Lamb', 'Quick Fire', 'Pinky Winky', 'Vanilla Strawberry', 'Pee Gee', etc. are just fine for full sun and are hardy to Zone 3. Because of their hardiness, they don't require any special care.
---Justin, Senior Garden Editor, BHG.com