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Rhododendron indicum

Common Name(s):

Previously known as:

  • Azalea indica
Phonetic Spelling
roh-do-DEN-dron IN-dih-kum
This plant has high severity poison characteristics.
See below
Description

Southern Indian azalea is a small, semi-evergreen shrub in the Ericaceae (blueberry) family that is native to Japan. This compact azalea has a mature size of about 2 to 3 feet in both height and width. While it has a dense canopy it can spread. The genus name, Rhododendron, derives from the Greek words rhodo, which means rose, and dendron, meaning tree.  

This plant prefers partial shade and acicic well drained soil that is moist and high in organic material. It is intolerant of heavy and wet soils, drought, and excessive fertilization. It has a slow growth rate and requires a high level of maintenance including removing spent flower clusters immediately after flowering.  

Southern Indian azalea has showy, hot pink to burgundy flowers that bloom in mid to late spring and occasionally again in the fall. It works well in the landscape as an understory shrub mass planted or in small groups in woodland or naturalized areas, or as specimens in pollinator gardens where the flowers will attract bees. It can also be used as a low hedge or in a winter garden where its leaves turn attractive shades of red.  

Quick ID Hints:

  • Small shrub, sympodial growth, with crowded evergreen leaves in tiers
  • Twigs & leaves covered with reddish-brown hairs 
  • Flowers axillary, single in spring with funnel-form corolla
  • Calyx 5-lobed, elongated & pointed

Insects, Diseases, and Other Plant Problems: Insect problems include aphids, borers, lace bugs, leafhoppers, mealybugs, mites, nematodes, scale, thrips, and whitefly. Diseases include canker, crown rot, root rot, leaf spot, rust, and powdery mildew. 

While these shrubs remain very popular for landscape use, many cultivars are susceptible to Phytophthora root rot—this leads to leaf loss, reduced vigor, branch dieback, and wilting. Implement good cultural practices first, such as improving drainage with organic matter or berms and avoiding overwatering or overfertilization. However, if you have a site with a history of this disease, consider planting one of the root rot-resistant alternative species listed in the left-hand sidebar. 

For suitable alternatives, see this video created by Charlotte Glen as part of the Plants, Pests, and Pathogens series.

VIDEO Created by Elizabeth Meyer for "Trees, Shrubs and Conifers" a plant identification course offered in partnership with Longwood Gardens.

More information on Rhododendron.

Profile Video:
See this plant in the following landscapes:
Birdbath Nook Woodland Walk
Cultivars / Varieties:
'Coral Bells', 'Crimson Majesty', 'Formosa'
Tags:
#evergreen#showy flowers#poisonous#specimen#pink flowers#slow growing#shade garden#spring flowers#winter interest#rabbit resistant#mass planting#high maintenance#hedges#foundation planting#fantz#flowers late spring#evergreen shrub#small group plantings#winter color red#hot pink flowers#flowers early fall#problem for cats#problem for dogs#problem for horses#disease problems#shrub borders#woodland garden#wet soils intolerant#low hedge#flowers mid-spring
 
Cultivars / Varieties:
'Coral Bells', 'Crimson Majesty', 'Formosa'
Tags:
#evergreen#showy flowers#poisonous#specimen#pink flowers#slow growing#shade garden#spring flowers#winter interest#rabbit resistant#mass planting#high maintenance#hedges#foundation planting#fantz#flowers late spring#evergreen shrub#small group plantings#winter color red#hot pink flowers#flowers early fall#problem for cats#problem for dogs#problem for horses#disease problems#shrub borders#woodland garden#wet soils intolerant#low hedge#flowers mid-spring
  • Attributes:
    Genus:
    Rhododendron
    Species:
    indicum
    Family:
    Ericaceae
    Life Cycle:
    Woody
    Country Or Region Of Origin:
    Japan
    Wildlife Value:
    Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli. Deer browse this plant.
    Dimensions:
    Height: 2 ft. 0 in. - 3 ft. 0 in.
    Width: 2 ft. 0 in. - 3 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Poisonous
    Shrub
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Habit/Form:
    Dense
    Spreading
    Growth Rate:
    Slow
    Maintenance:
    High
  • Cultural Conditions:
    Light:
    Partial Shade (Direct sunlight only part of the day, 2-6 hours)
    Soil Texture:
    High Organic Matter
    Loam (Silt)
    Soil pH:
    Acid (<6.0)
    Soil Drainage:
    Good Drainage
    Moist
    Available Space To Plant:
    12 inches-3 feet
    NC Region:
    Coastal
    Piedmont
    USDA Plant Hardiness Zone:
    7b, 7a, 8a, 8b
  • Fruit:
    Fruit Type:
    Capsule
    Fruit Description:
    Fruits are a dehiscent 5-valved capsule.
  • Flowers:
    Flower Color:
    Pink
    Red/Burgundy
    Flower Inflorescence:
    Raceme
    Flower Value To Gardener:
    Showy
    Flower Bloom Time:
    Fall
    Spring
    Flower Shape:
    Funnel
    Flower Petals:
    4-5 petals/rays
    Flower Description:
    Flowers are axillary, single to rarely double, non hose-in-hose, bright red to scarlet to pinkish-red or white. There are 5 calyx lobes that are elongated, narrow, and acutely pointed. Corolla is funnel-form, 1-2" in size, have 5 lobes with the upper central lobe and sometimes the lateral pair bearing conspicuous maculation. They bloom in mid to late spring and sometimes again in the fall.
  • Leaves:
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Leaf Color:
    Green
    Deciduous Leaf Fall Color:
    Red/Burgundy
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Lanceolate
    Oblanceolate
    Leaf Margin:
    Crenate
    Serrate
    Hairs Present:
    Yes
    Leaf Description:
    Leaves are alternate, simple, crowded, and consist of evergreen (winter) leaves and deciduous (seasonal) leaves. Blades are narrowly lanceolate to oblanceolate, crenate-serrulate (slightly toothed), with scattered reddish-brown hairs on veins below. Petiole is pubescent with stiff reddish-brown hairs. Leaves turn reddish in the winter.
  • Stem:
    Stem Is Aromatic:
    No
    Stem Surface:
    Hairy (pubescent)
    Stem Description:
    Twigs are pubescent with stiff reddish-brown trichomes and has sympodial growth.
  • Landscape:
    Landscape Location:
    Woodland
    Landscape Theme:
    Shade Garden
    Winter Garden
    Design Feature:
    Border
    Foundation Planting
    Hedge
    Mass Planting
    Small groups
    Resistance To Challenges:
    Rabbits
    Problems:
    Frequent Disease Problems
    Poisonous to Humans
    Problem for Cats
    Problem for Dogs
    Problem for Horses
  • Poisonous to Humans:
    Poison Severity:
    High
    Poison Symptoms:
    Vomiting (not in horses), diarrhea, weakness, cardiac failure
    Poison Toxic Principle:
    Grayantoxin
    Causes Contact Dermatitis:
    No
    Poison Part:
    Bark
    Flowers
    Fruits
    Leaves
    Roots
    Sap/Juice