He wondered about rot or staining. Now she and her husband both relax and enjoy the special look of their window boxes. The flowers form the look. Transfer tender bedding plants to window boxes after all danger of frost has passed, or sow hardy annuals like candytuft, dwarf sunflowers, nasturtiums and cosmos directly into window boxes. Monochromatic schemes use flowers of a single color, like white, but be sure to vary the shapes and foliage for interest.
White salvia is a striking contrast to white asters.
Flowers with a blue base color, pink, blue, purple and fuchsia, enhance a gray or blue house. But brighten the effect by adding silver-gray highlight plants, such as dusty miller. Contrasting colors are good, such as orange and purple. Consider the light. If your home is flooded with sunshine, use strong colors.