Insect pests on hydrangea include aphids, leaf tiers, rose chafers and red spiders. Blue Prince' 'Compacta,' supposedly more compact than 'Nikko Blue' with darker green leaves. Coerulea,' perfect flowers a deep blue and ray flowers blue or white. 8-inch leaves, which turn bronze in fall. The white flower clusters are 6 to 10 inches wide in lacecap effect.
Old plants have a peeling, cinnamon-colored bark.
Grandiflora' has 6-inch clusters on a similarly sized plant. Leaves are 5 inches long and turn bronze in fall. Praecox' grows 10 to 15 feet tall and flowers in June. Blue Billow' is only 3 feet tall. Prepared by Marjan Kluepfel, HGIC Information Specialist, and Bob Polomski, Extension Consumer Horticulturist, Clemson University.