What Goes With a Rhododendron?

About Rhododendrons

• Though they have a reputation as deep shade-loving plants, most types of rhododendrons actually do best when placed in dappled shade, where at least some sunlight reaches the shrub through the local canopy. When it must be placed in areas with heavier shade, it helps when the plant receives a bit of morning sun, especially in areas where the midday sun can be intense. Rhododendrons prefer acidic soils with a pH of around 5.5 and should be placed in an area with moist but well-drained soil. Waterlogged rhododendrons are susceptible to a variety of root-rot diseases and will quickly decline. While many gardeners are probably most familiar with the popular evergreen rhododendrons, there also exist a number of deciduous types that boast a glorious spring flower show, as well. Rhododendrons are hardy in U.S. Department of Agriculture plant hardiness zones 4 through 8, though hardiness can vary, depending on the specific type of rhododendron.

Companion Trees

• In the wild, rhododendrons typically grow in the understory of a forest canopy and usually look leggier than landscape specimens. Avoid using shallow-rooted tree species, like some oaks and most maples, which will compete with the rhododendron for nutrients and water. Good tree companions to consider include the sourwood (Oxydendrum arboreum) and American holly (Ilex opaca), both of which grow well in USDA hardiness zones 5 through 9. Another potential companion is the worthy and vastly underused Japanese stewartia (Stewartia pseudocamellia), a four-season tree with attractive peeling bark and an unusual late-summer bloom time. It grows best in USDA zones 5 through 7. Also consider the Carolina silverbell (Halesia carolina), a showy spring-blooming American native that performs well in USDA hardiness zones 5 through 8.

Shrubs

• Rhododendrons need not be used en masse just because there are thousands of types to choose from. Varying the shrub companions planted nearby will also provide interesting foliage texture contrasts or even furnish blooms when the rhododendrons are finished flowering. Fetterbush (Leucothoe fontanesiana) has drooping stems with glossy, spearhead-shaped leaves that turn bronze over the winter, and grows best in USDA hardiness zones 5 through 8. The broad, deciduous leaves of the native spicebush (Lindera benzoin) are not only an important larval host for the spicebush swallowtail butterfly but also turn a brilliant yellow in autumn. It is hardy in USDA zones 4 through 9. For summer flowering interest, consider summersweet (Clethra alnifolia), hardy in USDA zones 3 through 9. Native witch hazel (Hamamelis virginiana), hardy in USDA zones 4 through 8, blooms fragrantly in late autumn or winter, an unusual feature in the garden when all else is dormant.

Perennials

• Toss out the notion that only hostas make good perennial companions for rhododendrons. Although it is true that the many thousands of varieties of hostas (Hosta species) boast interesting colors and an exceptional range, from USDA zones 3 to 8, other perennials work well, too. Try the spring-flowering astilbes (Astilbe species), hardy in USDA zones 4 through 9, which also enjoy the moist, acidic soils that rhododendrons prefer. An evergreen stalwart like the Christmas fern (Polystichum acrostichoides), hardy in USDA zones 3 through 9, stands up erectly in the summer but lays down flat in the winter, providing even cold-season interest. Perennial ground covers to consider include the creeping, vinelike teaberry (Gaultheria procumbens), hardy in USDA zones 3 through 7, and bearberry (Arctostaphylos uva-ursi), a mat-forming creeper that produces red berries in winter and is hardy in USDA zones 2 through 6.