Rhododendron schlippenbachii
Common Name(s):
- Phonetic Spelling
- rho-doh-DEN-dron shlip-pen-BAH-kee-eye
- This plant has high severity poison characteristics.
- See below
- Description
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Royal azalea is a woody, upright, rounded, deciduous shrub in the Ericaceae (blueberry) family. It is native to China, Japan, and Korea. Growing 6 to 8 feet tall and wide, its showy, fragrant flowers appear in April to May. The genus name derives from the Greek words rhodo, which means rose, and dendron, meaning tree.
Although royal azalea will grow in full sun, it prefers dappled sun or high open shade and moist, well-drained, acidic, humus-rich soil. It does not tolerate dense clay, so if you have clay soil, amend with organic material. The roots may rot if soil does not drain well. Plant the root ball high in the soil to help with drainage issues. Pruning, if desired, may be done after flowering.
Site this plant in a woodland or natural area. With its large size and showy flowers, it can be used as a dramatic specimen. Its flowers will also attract bees, butterflies, and other pollinators to a pollinator garden.
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. This plant tolerates browsing by rabbits but is frequently damaged by deer.
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.
- Profile Video:
- See this plant in the following landscape:
- Cultivars / Varieties:
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- Tags:
- Cultivars / Varieties:
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- Tags:
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Attributes:
- Genus:
- Rhododendron
- Species:
- schlippenbachii
- Family:
- Ericaceae
- Life Cycle:
- Woody
- Country Or Region Of Origin:
- China, Japan, Korea
- Wildlife Value:
- Flowers attract butterflies. Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli. This plant tolerates browsing by rabbits.
- Dimensions:
- Height: 6 ft. 0 in. - 8 ft. 0 in.
- Width: 6 ft. 0 in. - 8 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Perennial
- Poisonous
- Shrub
- Woody Plant Leaf Characteristics:
- Deciduous
- Habit/Form:
- Rounded
- Maintenance:
- Low
- Texture:
- Medium
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Cultural Conditions:
- Light:
- Full sun (6 or more hours of direct sunlight a day)
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
- Soil Texture:
- High Organic Matter
- Loam (Silt)
- Sand
- Soil pH:
- Acid (<6.0)
- Soil Drainage:
- Good Drainage
- Moist
- Available Space To Plant:
- 6-feet-12 feet
- NC Region:
- Mountains
- USDA Plant Hardiness Zone:
- 4a, 4b, 5a, 5b, 6a, 6b
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Fruit:
- Display/Harvest Time:
- Fall
- Fruit Type:
- Capsule
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Flowers:
- Flower Color:
- Pink
- Flower Inflorescence:
- Raceme
- Flower Value To Gardener:
- Fragrant
- Showy
- Flower Bloom Time:
- Spring
- Summer
- Flower Shape:
- Funnel
- Flower Petals:
- 6 petals/rays
- Flower Size:
- 1-3 inches
- Flower Description:
- 2 to 3 in. flowers in late spring to early summer; pale to rose pink; fragrant; open as leaves emerge
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Leaves:
- Woody Plant Leaf Characteristics:
- Deciduous
- Leaf Color:
- Green
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Whorled
- Hairs Present:
- No
- Leaf Length:
- 3-6 inches
- Leaf Description:
- Alternate, simple dark green leaves; 2 to 5.5 in. long; appears whorled
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Stem:
- Stem Is Aromatic:
- No
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Landscape:
- Landscape Location:
- Container
- Naturalized Area
- Woodland
- Landscape Theme:
- Butterfly Garden
- Pollinator Garden
- Design Feature:
- Specimen
- Attracts:
- Butterflies
- Pollinators
- Specialized Bees
- Resistance To Challenges:
- Rabbits
- Problems:
- Poisonous to Humans
- Problem for Cats
- Problem for Dogs
- Problem for Horses
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Poisonous to Humans:
- Poison Severity:
- High
- Poison Symptoms:
- Salivation, watering of eyes and nose, abdominal pain, loss of energy, depression, nausea and vomiting, diarrhea, weakness, difficult breathing, progressive paralysis of arms and legs, coma.
- Poison Toxic Principle:
- Andromedotoxin
- Causes Contact Dermatitis:
- No
- Poison Part:
- Bark
- Flowers
- Fruits
- Leaves
- Roots
- Sap/Juice
- Seeds
- Stems
