April. “This small shrub is perfect for gardeners with bitterly cold winters,” writes Patricia A. Taylor. “Its rose purple flowers reliably burst forth every spring, almost seeming to defy snows and frosts.”64 Note: Endangered in Kentucky. Zones: 5–9; PINK AZALEA, PINXTERBLOOM AZALEA (R. periclymenoides, syn. R. nudiflorum). Height: 4–7 feet. Ornamental Attributes: Light to dark pink fragrant flowers in April to May, yellow fall foliage. Note: Threatened in Ohio. Zones: 4–8; PINKSHELL AZALEA (R. vaseyi). Height: 10–15 feet. Spread: 3–10 feet. Ornamental Attributes: Eye-popping white to delicate pink flowers in late April, striking red fall foliage. Note: Very shade tolerant. Endemic to North Carolina. Endangered by development of its mountain habitats and over-collecting by horticulturalists. Zones: 5–7; RHODORA (R. canadense). Height/Spread: 2–4 feet. Ornamental Attributes: Bright purple blooms in early spring. Cold hardy species native to Canada south to Pennsylvania. Zones: 3–6; ROSEBAY RHODODENDRON, AMERICAN RHODODENDRON, GREAT LAUREL, WHITE LAUREL (R. maximum). Height/Spread: 4–15 feet. Ornamental Attributes: Showy, large white, pink, or purple flowers bloom June and July when few shade plants are flowering. “This old-fashioned favorite should be a staple in deep shade gardens.”65 Waxy, dark blue-green, leathery leaves on very cold-hardy plant that becomes a massive rounded shrub. Note: Threatened in Ohio. Zones: 3–7; SMOOTH AZALEA, SWEET AZALEA (R. arborescens). Height/Spread: 4–8 feet. Ornamental Attributes: Exceptionally hardy plant with clusters of very fragrant white or rose-tinged flowers perfuming a wide area in late spring to summer. Glossy orange-red fall leaves. Usually remains bush-like but can become tree-like with age. Readily crosses with other deciduous azaleas, so many plants labeled as true species are in fact natural hybrids. Native from New York to Alabama. Zones: 4–7; SWAMP AZALEA (R. viscosum). Height: 5 feet. Spread: 12 feet. Ornamental Attributes: Its very fragrant white to pink-flushed flowers bloom May to June; fall color is flame red to orange-maroon. Cultivation: Full sun, damp soil. A wetland shrub; does well in poorly drained areas. Note: Grows from Maine to Florida, and westward to Texas. Zones: 3–8; MOUNTAIN LAUREL. Family: Heath (Ericaceae). Genus: Kalmia (K. latifolia). Height/Spread: 5–15 feet. Large shrub, small tree. Ornamental Attributes: White or light pink flowers in May to July, contorted stems, twisted trunk. Writing about the Midwest, Weeks and Weeks note that “this is one of the most spectacular native shrubs.”66 Can use as a hedge. Nature Note: The native species have special value to native bees, including bumblebees (p. 61) and solitary native bees. The Cornell azalea bee is always found near azaleas; azalea pollen is its favorite food. Tiny insects and ruby-throated hummingbirds (p. 91) visiting for nectar pollinate the flowers. Nesting birds, including hummingbirds, seek the tiny insects to eat and feed to their baby birds. Foliage provides wildlife and birds with shelter and nesting places. Native rhododendrons and azaleas host 51 species of butterflies and moths, including the gray comma butterfly, azalea sphinx, and the slender clearwing moth, which lays her eggs only on heath family plants. Zones: 5–9.
Flame azalea (Rhododendron calendulaceum)
For more heath family plants see BEARBERRY, p. 156; BLUEBERRY, p. 27; CRANBERRY, p. 28; DEERBERRY, p. 138; HUCKLEBERRY, p. 28; SOURWOOD TREE, p. 186.
Orchard mason bee (Osmia lignaria)
Mountain laurel (Kalmia latifolia)
Another Native Alternative:
RED BUCKEYE, p. 33.
Nonnative:
ROSE. Family: Rose (Rosaceae). Genus: Rosa. Origin: Europe, Asia. Ornamental Attributes: Pink flowers. Erect, climbing, or trailing woody species, varieties, and cultivars, often with suckers and sharp prickles, produce sometimes fragrant flowers in a variety of shapes and colors. “Distinguishing different species of roses (whether native or exotic) can be difficult,” notes John Hilty.67 Cultivation: Sun, well-drained soil. High maintenance: mounding, protection from freeze-thaw cycles, spraying, fertilizing, watering, pruning. Pesticides to fight black spot and other diseases also kill butterflies, bees, and other beneficial insects. Cultivars sold as disease “resistant” are resistant to some, but not all diseases. All cultivated roses (shrub type, hybrid tea, floribunda, grandiflora, and miniature roses), including landscape roses in the popular Drift, Oso Easy, Flower Carpet, and Knock Out series, are considered susceptible to the highly contagious Rose Rosette Disease (RRD), which can destroy entire beds of roses. The increased use in residential and commercial landscapes of mass plantings of cultivated shrub roses is causing RRD to widely expand. In contrast, many native wild rose species have been reported as resistant to RRD.68 CABBAGE ROSE, PROVENCE ROSE (R. centifolia). Zones: 5–8; COMMON BRIAR, DOG ROSE (R. canina). Zones: 6–9; DAMASK ROSE (R. × damascena [gallica × moschata]). Zones: 4–9; FRENCH ROSE (R. gallica). Zones: 4–8; JAPANESE ROSE, RUGOSE ROSE (R. rugosa). Zones: 4–8; MEMORIAL ROSE (R. wichuraiana). Zones: 3–8; MULITIFLORA ROSE, JAPANESE ROSE (R. multiflora). Zones: 3–8; REDLEAF ROSE (R. ferruginea, syn. R. rubrifolia). Zones: 2–8; SCOTCH ROSE (R spinosissima). Zones: 4–8; SWEETBRIAR ROSE (R. rubiginosa). Zones: 4–9. Ecological Threat: These nonnative roses are naturalized or invasive in midwestern states. Nonnative roses sometimes hybridize with native roses, raising the possibility of altering the gene pool of the native species.
Nearly Wild rose (Rosa x ‘Nearly Wild’)
Native Alternatives:
PRAIRIE ROSE, SUNSHINE ROSE, PRAIRIE WILD ROSE, ARKANSAS ROSE. Family: Rose (Rosaceae). Genus: Rosa (R. arkansana and R. arkansana suffulta). Height: 1–4 feet. Ornamental Attributes: Fragrant crimson to pink or sometimes bicolored yellow-centered flowers with golden stamens June to August. “An almost ever-present feature of native prairies.”69 Cultivation: Full to part sun, dry or medium soil. Drought
