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TREES & plants

Catawba Rhododendron

Flowers and leaves of catawba rhododendron.

Catawba rhododendron is a large-leaved, evergreen shrub reaching 6 to 10 feet high with large, lilac-purple flowers borne in clusters (trusses) in mid-to late spring. Excellent for shade gardens or in a sheltered site. Requires well-drained, acidic soils. Native to southeastern U. S.

This plant has some cultivated varieties. Go to list of cultivars.

 

Botanical name: 
Rhododendron catawbiense
All Common Names: 
Catawba rhododendron, catabaw rosebay, mountain rosebay
Family (English): 
Heath
Family (Botanic): 
Ericaceae
Tree or Plant Type: 
  • Shrub
Native Locale: 
  • North America
Landscape Uses: 
  • Massing, 
  • Mixed border, 
  • Specimen
Size Range: 
  • Large shrub (more than 8 feet)
Light Exposure: 
  • Partial sun/shade (4-6 hrs light daily), 
  • Full shade (4 hrs or less of light daily)
Hardiness Zones: 
  • Zone 4, 
  • Zone 5 (Chicago), 
  • Zone 6, 
  • Zone 7, 
  • Zone 8
Soil Preference: 
  • Acid soil, 
  • Moist, well-drained soil
Season of Interest: 
  • Early winter, 
  • Mid winter, 
  • Late winter, 
  • Late spring, 
  • Early summer
Flower Color & Fragrance: 
  • Pink, 
  • White
Shape or Form: 
  • Irregular, 
  • Mounded, 
  • Open, 
  • Round
Growth Rate: 
  • Slow
More Information: 

Size & form

A large rounded, evergreen shrub reaching 6 to 10 feet high with dense foliage near the ground.

Tree & Plant Care

Grows best in part shade in a protected site. Morning sun and afternoon shade is best in hot summers.
Prefers organic-rich, acidic, well drained soils. Amend soil at time of planting.
Good drainage is essential, roots are shallow and fibrous so avoid wet clay soils, which can cause root rot.
Plants benefit with a layer of mulch to retain moisture and moderate soil temperature fluctuations.
Plants can show chlorotic symptoms in high pH soils.
Flowers on older wood and are hardy to -25°F. Deadheading not necessary but can be snipped off carefully after blooming.
To protect plants from winter winds, wrap a cylinder of fencing around plant and filled with leaves once the ground freezes.
Rhododendrons are susceptible to black walnut toxicity and should not be planted near walnut trees.

Disease, pests, and problems

Black vine weevils, borer, lace bugs, aphids, scale, thrips, mites, canker, crown rot root rots, powdery mildew and rust

Native geographic location and habitat

Native to eastern U. S., Allegheny Mountains, WV, GA, and AL

Bark color and texture 

New stem growth yellowish green becoming brown with age.

Leaf or needle arrangement, size, shape, and texture

Alternate, 3 to 6 inch long and 2 inch wide, dark green, leathery, elliptical leaves.

Flower arrangement, shape, and size

Large, 5 to 6 inch clusters (trusses) of individual lilac-purple flowers in late May to early June.
Corolla has yellow to brown markings inside.

Fruit, cone, nut, and seed descriptions

A 5-valved dehiscent capsule.

Cultivars and their differences 

All cultivars similar to species but vary in flower color.

White Catawba Rhododendron (Rhododendron catawbiense f. album):  pure white flower trusses with greenish spotting, excellent hardiness -25° F.

English Rose Catawba Rhododenron (Rhododendron catawbiense 'English Roseum'): light rose trusses, hardy to -25° F.

Nova Zembla Catawba Rhododendron (Rhododendron catawbiense 'Nova Zembla'): red to lavender-red trusses, hardy to -25° F.

Roseum Elegans Catawba Rhododendron (Rhododendron catawbiense 'Roseum Elegans'): old-fashioned cultivar, lavender-pink trusses, hardy to -25° F.

Rhododendron catawbiense or Catawba Rhododendron