The dwarf mugo pine (Pinus mugo var. pumilio) grows to 6 feet tall and has bright green, evergreen needles. It's hardy in USDA zones 2 to 9 and grows well in sun to partial shade and moist soil. The "Diablo" Eastern ninebark (Physocarpus opulifolius "Diablo") also grows well with the nandina. Hardy in USDA zones 2 to 7, this deciduous cultivar has purple-red foliage and blooms with small, pink-white flowers. It thrives in sun or partial shade and tolerates wet to dry soil.
The "Blue Pacific" juniper (Juniperus conferta "Blue Pacific") also complements nandinas. This evergreen grows to 1 foot tall but spreads to 9 feet, creating a dense mat of blue-green foliage. It's hardy in USDA zones 5 to 9 and grows in sun or light shade and well-draining soil.
For a splash of bright color near your nandina shrub, plant coral bells (Heuchera sanguinea). These perennials grow to 18 inches tall and bloom with pink and red blossoms atop heart-shaped foliage. Coral bells are hardy in USDA zones 3 to 8 and prefer rich, well-draining soil in sunny to partially shaded sites. For early spring blossoms and attractive summer foliage, plant wild ginger (Asarum spp.). This little perennial grows to 10 inches tall and prefers moist, shaded spots, so plant it in the shade cast by your nandina. It's hardy in USDA zones 4 to 8 and has dark, heart-shaped leaves.
Miscanthus (Miscanthus sinensis) grass grows in a variety of sizes and colors, such as "Silver Feather" a 7-foot-tall cultivar that's hardy in USDA zones 4 to 9, and "Gracillimus" or maiden grass, which forms an 8-foot mound and is hardy in USDA zones 5 to 9. Maiden grass grows in sun to light shade and well-draining soil. For a smaller grass, plant pink muhly or deer grass (Muhlenbergia capillaris). This 3-foot-tall grass is hardy in USDA zones 6 to 9 and grows in upright clumps of thin, airy foliage. It blooms with pink, purple and gray inflorescences and grows well in sunny to lightly shaded sites with well-draining soil.