Little Lamb (Hydrangea paniculata 'Little Lamb')
Paniculata hydrangeas will grow and bloom in a wide variety of climates (hardy to Zone 3!).
If your weather is too cold to support the pink and blue hydrangeas or if your landscape doesn't have much shade, consider growing one of the many types of paniculatas.
North or south, we can all enjoy them. Many paniculata blooms develop a lovely pink shade as the blooms age, extending their beauty into the fall.
Paniculatas often get very large. 8-10 feet tall and wide is not unusual. Since you may want to prune this plant up and over your perennial border or let it weep over your Hydranga serratas.