Hydrangeas feature their huge globe-shaped flowers in pink, white, red and blue. Their biggest prerequisite is shade or filtered sun, and plenty of water on our hottest days. Besides providing an abundance of color in shady areas, hydrangeas fill an important niche in the garden. For instance, as shrubs go, they bloom for a long time - literally all summer. They're versatile in that you can keep them pruned to manageable size or let them go to rather gigantic proportions.
Hydrangeas are also deciduous in that they lose their leaves in winter.
Therefore, they are perfect as a background planting, and are ideal companions to azaleas, camellias and rhododendrons. Yet, my favorite reason for growing hydrangeas is their interesting ability to change color according to the pH level of the soil. There aren't many plants that you can change the color of flowers by fertilizing. Plus, there aren't too many blue flowers with 10-inch heads. This forced feeding needs to take place a couple times in early spring and spring.