Habitat

• native to southern Appalachian mountains from Virginia through Georgia
• zone 4

Habit and Form

• an evergreen shrub
• typically 6' to 10' tall with an equivalent spread
• can get to 20' tall
• mounded to upright in habit
• generally dense under ideal conditions, but becomes more open in dense shade or in unfavorable sites

Summer Foliage

• alternate leaves, clustered towards the shoot apex
• evergreen, elliptical leaves
• 3" to 6" long and 1" to 2" wide
• color is dark green
• leaves quite leathery

Autumn Foliage

• no fall color
• evergreen

Flowers

• large flower buds at the shoot apex
• lilac-purple to magenta color with green or orange-speckled throat
• individual flowers are 2.5" across and funnel-shaped
• flower clusters are 5" to 6" in diameter and comprised of 5 to 10 flowers
• blooms in mid to late May
• quite showy in bloom

Fruit

• dehiscent capsule
• not ornamentally attractive

Bark

• gray-brown
• not often highly visible through evergreen foliage

Culture

• partial shade to full sun
• prefers moist, cool, acidic, well-drained, organic soil
• avoid dry, hot windswept sites
• removal of spent blossoms encourages new growth and flower bud set
• transplant from containers or B&B.

Landscape Use

• as a specimen
• in groups or massed
• shrub border
• woodland setting
• useful in partially shaded areas
• for decoration from both flowers and foliage

Liabilities

• black vine weevil
• phytophthora root rot
• desiccation in dry, windswept, sunny locations
• chlorosis on high pH soils

ID Features

• broadleaf evergreen
• large, showy flowers
• flower bud dramatically larger than vegetative buds
• leaf-like subtending bracts do not surround the flower bud as in R.maximum
• leaves large, clustered at end of shoot in an alternate arrangement

Propagation

• by seed
• by stem cuttings in late summer, fall and winter
• tissue culture for selections and new hybrids

Cultivars/Varieties

Often, the large-leaf rhododendrons are all grouped together under the heading R. catawbiense for convenience. This organization gives the impression that these dozens/hundreds of cultivars are all selections or hybrids of this species. In fact, most are complex interspecific hybrids and many contain no R. catawbiense blood. The varieties and cultivars listed below are either selections of R. catawbiense or F₁ hybrids (first generation) with R. catawbiense. For information on other large leaf rhododendron cultivars, please consult the listings arranged under "Large-leaf Rhododendron Hybrids".

var. album - The white flowers of this selection open from buds that are tinged lilac. This form features dark green foliage. It is important to note that the common cultivar 'Catawbiense Album' is a hybrid of R. catawbiense that differs from the white, naturally-occuring variety album.

var. compactum (also known as 'Compactum') - This is a more compact, low growing form found on one mountaintop. It only grows to about 3' tall.

'Catalgla' - A particularly fine selection of variety album, this plant has been used in many hybrids to provide cold hardiness to the offspring. It is very cold hardy to -25 F.

'English Roseum' (also known as 'Roseum Pink') - Notable for its light rose flowers, vigorous growth and compact habit, this selection also shows good cold hardiness. It is a dependable mainstay of New England gardens. It is probably a hybrid.

'Grandiflorum' - Hardy to -25 F with distinctive lilac-colored flowers, this selection also displays attractive plant habit. It is probably a hybrid of R. catawbiense.

'Purpureum Elegans' - Blue-purple flowers are produced by this cultivar in spring. It shows good cold hardiness and plant habit. It is probably a hybrid.

'Roseum Elegans' - The flowers of this popular cultivar are rose-like and somewhat small. It is a vigorous grower with good habit. This cultivar has become a mainstay in New England gardens -- probably the most common selection. The plant is very dependable and probably a hybrid. Some horticulturists criticize its monotonous use and rather brash flower color.