A bigleaf hydrangea, 'Nikko Blue' is a woody deciduous flowering shrub offering year-round interest. 'Nikko Blue' blooms earlier than many and creates a season-long floral display, blooming in showy mophead inflorescences on old wood beginning in summer and lingering into fall. The large 4- to 5-inch globose clusters of *pink or blue florets are held aloft fleshy, elliptic, serrate to dentate leaves on long, strong stems. The flowers are long lasting and make excellent cuts for fresh and dried arrangements.
After the first frost, flower clusters turn tan to caramel, and along with the shredding and peeling papery brown bark on mature plants that reveals glimpses of the underlying cinnamon hue of stems and branches, they add a textural element to the winter garden, especially pleasing in a snowy landscape. The hollow stems also provide nesting habitats for bees.
With cain-like growth, this dense, multistemmed, suckering shrub has an erect, rounded habit and a rapid growth rate. Easy to grow and maintain, Hydrangea 'Nikko Blue' prefers some morning sun and afternoon shade; rich, medium moisture, well-draining soil; and plenty of water. A shade-loving shrub, hydrangea can tolerate more sun if the soil is kept consistently moist.
*Hydrangea macrophylla change colors with the pH of the soil. They turn pink in alkaline soil and blue in acid soils.
