Genus Hydrangea Species macrophylla Cultivar 'PIIHN-11' Common Name Endless Summer® Bloomstruck®Hydrangea Patent ID 25566 Height 3 to 4 Feet Spread 4 to 5 Feet Habit Mounded habit. Moderate growth rate. Zone 4 to 9 Culture Partial shade. Flower Large, round blue or pink flowers, depending on soil pH. Blooms June-October. Flower Color Blue/Pink Foliage Dark green foliage, thick leaves. Striking red stems. Deciduous. Categories: Deciduous Shrub Endless Summer® Hydrangea Description Photo courtesy of Bailey Nurseries.