Hiryu Azalea Rhododendron ponticum

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

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.