Hydrangea, Endless Summer® The Original Macrophylla HydrangeaEndless Summer Hydrangea is a small deciduous shrub and has serrated dark green leaves with no fall color. Its mophead flowers bloom in waves through summer on both new and old wood with color that depends on the soil PH acidic soils produce sky blue flowers, while alkaline soils produce pink flowers that darken to pink blue with maturity. The flowers attract butterflies and pollinators. Best bloom in partial sun and rich, moist well drained soils.