Hiryu Azalea Rhododendron ponticum
Other Common Name(s):
Previously known as:
- Rhododendron x obtusum
- Phonetic Spelling
- rho-do-DEN-dron PON-ti-kum
- This plant has high severity poison characteristics.
- See below
- Description
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Dependable woody, dwarf evergreen or deciduous shrub in the Ericaceae family that is dense and spreading and grows between 3-4' tall. Kurume hybrid azaleas are hybrid crosses between R. kiusianum, R. kaempferi, R. sataense and R. obtusum. Plant it in mass in a shrub border, use as a foundation planting, specimen or in a woodland garden. This plant is used in bonsai. This plant blooms in mid spring, usually 1-2 weeks before R. indicum. The persistent evergreen leaves are smaller than the seasonal deciduous leaves. Seasonal leaves are subequal the size of the persistent leaves of R. indicum. In general, flowers and leaves are smaller than those of R. indicum with similar structures, but larger versions overlap with smaller versions of R. indicum, hence why they are often confused with each other. It is a very common spring blooming azalea with hundreds of cultivars. Hose-in-hose versions are distinct with the petalois calyx surrounding the similar appearing corolla. Double flowers have petaloid stamens. All parts of the plant are poisonous when ingested. This plant prefers partial shade. 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. It has pest and disease problems, especially fungal diseases.
Insects, Diseases, and Other Plant Problems: Rhododendrons are susceptible to insect and disease problems. Insect problems include aphids, borers, lacebugs, leafhoppers, mealybugs, mites, nematodes, scale, thrips and whitefly. Diseases include canker, crown rot, root rot, leaf spot, rust, and powdery mildew. Full sun can scorch the leaves and the roots rot if soil does not drain well. A healthy plant in the right place with proper maintenance should have few problems. This plant is frequently damaged by deer.
Quick ID Hints:
- Dwarf semigreen shrub with sympodial growth, crowded leaves
- Twigs & leaves with reddish-brown hairs
- Flowers axillary, solitary, in spring with a funnel-form
- Flowers hose-in-hose, single or double
- Calyx lobes short, broad, obtuse
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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- 'Pink Pearl'
- 'Pink Pearl'
- 'Pink Pearl'
- Tags:









- Cultivars / Varieties:
-
- 'Pink Pearl'
- 'Pink Pearl'
- 'Pink Pearl'
- Tags:
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Attributes:
- Genus:
- Rhododendron
- Species:
- ponticum
- Family:
- Ericaceae
- Life Cycle:
- Woody
- Country Or Region Of Origin:
- Bulgaria, Lebanon, Caucasus
- Wildlife Value:
- Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli.
- Dimensions:
- Height: 3 ft. 0 in. - 4 ft. 0 in.
- Width: 2 ft. 0 in. - 5 ft. 0 in.
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Whole Plant Traits:
- Plant Type:
- Poisonous
- Shrub
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Deciduous
- Habit/Form:
- Dense
- Spreading
- Growth Rate:
- Slow
- Maintenance:
- High
- Texture:
- Medium
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Cultural Conditions:
- Light:
- Partial Shade (Direct sunlight only part of the day, 2-6 hours)
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Fruit:
- Fruit Type:
- Capsule
- Fruit Description:
- Fruits are a dehiscent 5-valved capsule
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Flowers:
- Flower Color:
- Pink
- Purple/Lavender
- Red/Burgundy
- White
- Flower Value To Gardener:
- Showy
- Flower Petals:
- 4-5 petals/rays
- Flower Description:
- Flowers are axillary, single to double or hose-in-hose but rarely hose-in-hose double, and are rose-pink to red to purple to violet or white in color. There are 5 calyx lobes that are short, broad, and obtuse. Corolla is funnel-form and 1-2" in size. It has 5 lobes with the upper central and sometimes the lateral pair bearing inconspicuous to conspicuous maculation. They have 5-10 stamens.
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Leaves:
- Woody Plant Leaf Characteristics:
- Broadleaf Evergreen
- Deciduous
- Leaf Color:
- Green
- Leaf Feel:
- Glossy
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Leaf Shape:
- Elliptical
- Obovate
- Leaf Margin:
- Crenate
- Hairs Present:
- Yes
- Leaf Length:
- 1-3 inches
- Leaf Description:
- Leaves are alternate, simple, glossy, and consist of evergreen (winter) leaves and deciduous (seasonal) leaves. Blades are elliptic to obovate, crenate-serrulate, with scattered reddish-brown hairs on veins below. Petioles are pubescent with stiff reddish-brown hairs. They grow between 1.5-4" long.
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Stem:
- Stem Color:
- Brown/Copper
- Stem Is Aromatic:
- No
- Stem Description:
- Twigs are pubescent with stiff reddish-brown trichomes and have a sympodial growth.
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Landscape:
- Landscape Location:
- Woodland
- Landscape Theme:
- Pollinator Garden
- Design Feature:
- Border
- Foundation Planting
- Mass Planting
- Small groups
- Specimen
- Attracts:
- Bees
- Pollinators
- Specialized Bees
- Problems:
- 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