Rhododendron bakeri x viscosum

This native azalea is a hybrid of two well-loved wild species, the Cumberland azalea, Rhododendron bakeri, of the southern Appalachians, and the swamp azalea, Rhododendron viscosum, of wet woodland edges across the East. From the Cumberland azalea the cross takes warm color and a rounded, ball-shaped truss; from the swamp azalea, whose name viscosum means sticky, for the glandular, clammy surface of the flowers, the hybrid takes adaptability to humid ground and a late season of bloom. The genus name Rhododendron means rose tree in Greek.

The flowers open in warm peachy-salmon tones, funnel-shaped and gathered in rounded clusters, blending the reddish fire of the Cumberland azalea with the softer coloring of the swamp azalea parent. Bloom comes late, from late spring into summer, after most native azaleas have finished, so the shrub carries color into the quieter weeks of the season. These blossoms are grown chiefly for that warm late color rather than for strong scent, though a faint sweetness can linger from the swamp-azalea side.

The swamp azalea parentage gives this hybrid real adaptability, an unusual tolerance for damp, humid, even seasonally wet ground that defeats many azaleas, though the plant still wants drainage at the root. Like all of the wild azaleas, the shrub is grown for flower and form and never for eating: every Rhododendron carries grayanotoxins in leaf and nectar and should not be tasted by people or pets. The late flowers feed pollinators when little else in the shade garden is blooming.

Compact and upright at six to eight feet, this hybrid suits the woodland garden, a moist shaded border, or the edge of a rain garden or pond where damp ground would trouble other shrubs. Give partial shade, morning sun with afternoon relief, and a moist, acidic, well-drained soil rich in organic matter, with a cool mulch over the shallow roots. The dark green summer leaves take on attractive fall color, and the plant combines well with ferns, summersweet, and other moisture-loving natives for a long, layered season.