This mid- to late-spring showpiece forms a multi-stemmed, rounded shrub 4 to 8 feet tall with elegant, light-pink flowers that smell of cinnamon and cloves. Each flower has super-long stamens that curve like eyelashes, a distinguishing feature of our native azaleas. Smooth, blue-green, deciduous leaves turn shades of bronze-red and purple in the fall, and the plant is extremely cold hardy. It flourishes in part shade and moist, acidic, loamy, well-drained soils, and it adapts to clay and sandy soils. Unlike many azaleas, this species has a marked tolerance to high pH. You'll want to give this spring stunner 6 o 12 feet to spread and display its masses of clustered blooms.
R. prinophyllum is a facultative wetland species, meaning that it usually occurs in wetlands but may occur in non-wetlands. In wet habitats, it's often located on drier microsites within the communities. Its native range is the northeast US and eastern Canada. It's rarely found in Ohio, where it is classified as threatened. The genus name comes from the Greek words rhodo, which means rose, and dendron, meaning tree. Other common names are early azalea and election pink.
Another Rhododendron species, pinxterbloom (R. periclymenoides), is very similar to roseshell azalea. However, pinxterbloom's flowers range in color from white to pink to deep rose, while roseshell's are more uniformly pink and have a cinnamon-clovelike fragrance. In Ohio, these species sometimes grow in the same areas, where they can hybridize and become nearly impossible to tell apart.
Native habitats include coniferous or mixed forests, wooded slopes, thickets, open rocky areas, lake margins, bogs, swamps, peaty wetlands, and river banks. Perfect for understory shrub or mixed borders, foundation plantings, shade gardens, or use as a hedge or privacy screen.
Plant Characteristics:
Grows 3-8' tall and wide.
Prefers part sun. Needs protection from afternoon sun, which can scorch the leaves.
Prefers acidic, moist, well-drained soils but adapts to clay and sandy soils with higher pH. Doesn't tolerate dense clay.
Blooms May-June with tubular, 5-parted, light-pink flowers bearing 5 stamens. These give way to elongated capsules August-October that split open to release seeds.
Alternate, simple, elliptical, bright green leaves have smooth or toothed margins.
Reproductive System: male and female parts are on the same flower (perfect). The structure of the flower has been presumed to encourage cross-pollination, but studies show that roseshell azalea can rely on self-fertilization when pollinators are scarce. Thus, the plant is considered highly self-compatible.
Wildlife Value:
Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli. Hummingbirds, butterflies and other pollinators are attracted to the nectar. Provides shelter and cover for birds and mammals. Tolerates rabbit browse.
Medicinal, Edible, and Other Uses:
The Cherokee used infusions of the plant as a gynecological aid, and peeled bark and twigs may have been used to treat rheumatism.
Caution: All parts of the plant are poisonous to humans, horses, cats, and dogs.
Resources:
Dawes Arboretum: https://dawesarb.arboretumexplorer.org/taxpn-27540.aspx
Holden Forests and Gardens: https://holdenfg.org/blog/ohios-native-rhododendrons/#:~:text=Our%20first%20native%20species%20is,on%20fire%20during%20blooming%20season
Gardenia.net
North Carolina Extension: https://plants.ces.ncsu.edu/plants/rhododendron-prinophyllum/
The Plant Native: https://theplantnative.com/plant/azaleas/