SCIENTIFIC NAME: Hydrangea macrophylla
COMMON NAME: florists hydrangea, big leaf hydrangea, smooth hydrangea
FLOWERS: Big clusters of flowers that are either blue (acid soil) or pink (alkaline soil). Usually flowers in May. The inflorescence is usually rounded, but some cultivars have a flat inflorescence.
LEAVES: Opposite and coarsely serrated. Fleshy.
GROWTH HABIT: Grows 3' to 6' tall as a shrub.
OTHER: Hardy from zone 6 to 9. Likes full sun to part shade. Can manipulate flower color by adding limestone or aluminum sulfate to the soil. There are many cultivars available. In full sun foliage will wilt during midday and will regain turgidity by late afternoon.