These companion plants add contrast, texture, and color to hydrangea plantings. Credit: I am happy taking photographs. / Getty ImagesHydrangeas are among the most popular flowering shrubs among gardeners, beloved for their green foliage and bouncy blue, pink, white, or purple blooms. While they look beautiful on their own, pairing them alongside other beautiful perennials creates a garden rich with texture and color. Plus, some perennials can he…