Hydrangea macrophylla 'Blue Cassell' BLUE CASSELL™ HYDRANGEA

3-4 ft. (Zone 5)  Huge blue (or pink) lacecap flowers that bloom on old and new wood.  Flower color varies by variety and by soil ph.
 
General Hydrangea Lacecap type

Hydrangeas with lacecap type flowers have small fertile flowers surrounded by large showy outer petals which form a pinwheel effect. Flower color varies by variety and by soil ph.  Acidic ph for blue color, alkaline ph for pink.  Plant in part-shade to part-sun in well-drained organic soil.  Flower buds form on previous years stems.  Bloom in summer.