How to Encourage Blooming of Nikko Hydrangea for Next Year

Prune the Nikko Blue immediately after the shrub finishes blooming in early summer. Because this hydrangea will bloom next year on growth it puts forth during the remainder of the current growing season, waiting to prune may mean removing future blossoms. Shape the hydrangea shrub by removing not more than the outer third of each stem.

Fertilize the hydrangea by mixing the fertilizer with water according to package recommendations. Add fertilizer around the base of the plant in early spring, late spring and again in mid-summer. Avoid over-fertilizing the hydrangea because an overabundance of nitrogen may inhibit blossoming.

Apply about 4 inches of wood chips or shredded bark around the base of the hydrangea around the time of the first frost. Cover the entire soil area from the center stems out to the drip line with mulch to insulate the root system.

Cover the Nikko Blue with a burlap blanket in early spring after the plant begins to leaf out if you expect an overnight spring frost. Drape the blanket over the plant the evening before the frost and secure it around the soil with bricks. Remove the blanket the next morning after the air temperature rises above freezing. Protect the hydrangea using this method every time you expect freezing temperatures.