Before planting anything around the electrical box, check with the utility company about required clearances around the box. Remember that workers will occasionally have to access the box. Anything you choose to plant there should tolerate occasional abuse and trampling. Ornamental grasses are often a good choice to screen utility boxes. Miscanthus cultivars and fountain grass (Pennisetum alopecuroides) grow tall enough to disguise the boxes. As a bonus, they will screen the box in winter too. For a period in spring, right after you cut down the grass, you'll be able to see the utility box. But the grass will quickly grow up and hide it again. For color, combine the grasses with low-maintenance perennials, such as purple coneflower (Echinacea purpurea) and black-eyed Susan (Rudbeckia hirta), or annuals that will hold up in the sun, such as salvia (Salvia) or narrowleaf zinnia (Zinnia angustifolia).