Crocosmia
With saber-like leaves and colorful flowers, crocosmia (or its cousin gladiolus) will make a striking contrast to Orienpets. Crocosmia also needs full sun and well-drained soil, and the flowers attract hummingbirds. Plant the small, bulb-like corms in fall, when you would plant the lilies.
Lilacs
Plant lilacs behind Orienpets; they'll bloom first, adding color and sweet scents to your garden, then their dark green foliage will serve as a backdrop for the lilies.
Salvias
Choose a short salvia variety for the front of your bed, where it will help hide the lilies' bare lower stems. Most salvias will stay between 18 and 36 inches tall and do best in full sun or part shade and well-drained soil.