Invincibelle Sublime hydrangea ( H. arborescens ) ushers in a new day for full-sized smooth hydrangeas, with cloud-like mophead flowers floating above the plant on super-sturdy stems. Each floret of the big, fluffy blooms is a deeply saturated tourmaline-green that looks refreshing and intriguing in the garden all summer long. Very dark green foliage sets off the lively green of the blooms. Makes a fantastic cut flower, both fresh and dried, if you can bring yourself to remove them from the fabulous plant.