Hydrangea 'Endless Summer Blue' (close-up above and full-plant view below) (from my garden, Oct. 3, 2016). This mophead hydrangea bears many huge, dome-shaped delicate clusters of papery flowers. It has the most beautiful trait of having the ability to change the color of the blooms. Depending on the pH level of the soil, the color can be blue, white or pink. I inadvertently over-pruned this bush last fall cutting off all the buds that would bloom the following year. Instead of getting the usual 20 or more blooms, the bush grew large with many green leaves but no flowers. Now in Autumn when all almost all other plants have finished, a single beautiful giant blue flower has unexpectedly bloomed.