For many gardeners, hydrangeas are a must-have for the flowerbed or landscape. These classic shrubs provide showy summer color after many of the spring-blooming flowers have stopped. Flower panicles in hues of white, pink, blue, purple and other colors cover the healthy, hardy shrubs and make a huge impact in the garden. The flowers are also treasured as cut flowers and are very showy in fresh floral displays. With some hydrangea varieties, the soil's acidity impacts the color of the blooms. Thanks to modern breeding efforts, hydrangeas are now available in a variety of colors and sizes.