Common Name: dahurian rhododendron
Type: Broadleaf evergreen
Family: Ericaceae
Native Range: Eastern Siberia, Mongolia, northern China, Japan
Zone: 5 to 8
Height: 4.00 to 6.00 feet
Spread: 4.00 to 6.00 feet
Bloom Time: March to April
Bloom Description: Pink to violet-pink
Sun: Part shade
Water: Medium
Maintenance: Medium
Suggested Use: Hedge
Flower: Showy
Leaf: Evergreen
Attracts: Hummingbirds, Butterflies
Other: Winter Interest
Tolerate: Rabbit
Culture
Best grown in acidic, humusy, organically rich, moisture-retentive but well-drained soils in part shade. Prefers a sun dappled shade. Foliage may scorch in full sun. Acidify soils prior to planting and thereafter as needed. Plant in a location protected from strong winter winds. Good soil drainage is essential (doesn’t like “wet feet”). Poor drainage inevitably leads to root rot, therefore raised beds/plantings should be considered in heavy clay soils such as those present in much of the St. Louis area. Shallow, fibrous root systems (do not cultivate around plants) will benefit greatly from a mulch (e.g., wood chips, bark or pine needles) to help retain moisture and stabilize soil temperatures. Roots must never be allowed to dry out. Clip off spent flower clusters immediately after bloom as practicable.
Noteworthy Characteristics
Rhododendron dauricum, commonly called dahurian or daurian rhododendron, is a compact, small-leaved, deciduous to semi-evergreen rhododendron that is native to sub-alpine forests and forest margins in the Altai Mountains from Russia into Mongolia, eastern Siberia, Sakhalin Island, northern China, Japan and Korea. This rhododendron was reportedly first collected in Dauria, a mountainous region in southeastern Siberia east of Lake Baikal, hence the specific epithet and common name. It is a compact, vigorous, early-blooming shrub that typically matures over time to 4-6' tall and as wide. Open funnel-shaped, pink to violet pink flowers (to 1 1/2") bloom in March-April in the St. Louis area (as early as January in warm winter climates) in terminal clusters at the branch ends or from the upper leaf axils. Small, leathery, shiny green, elliptic to oblong leaves (to 2" long) are semi-evergreen with purplish tints in mild winter locations, but close to deciduous near the northern edge of the growing range. Plant vigor, excellent winter hardiness, and early bloom make this an attractive plant for hybridization.
Rhododendron dauricum var. sempervirens (now Sempervirens Group) is an evergreen version of this species that was crossed with Rhododendron carolinianum to produce the Rhododendron PJM Group hybrids.
Genus name comes from the Greek words rhodo meaning rose and dendron meaning tree. Transferred from the Greek name for Nerium oleander.
Problems
Rhododendrons are susceptible to many insect and disease problems, including but not limited to canker, crown rot, root rot, leaf spot, rust, powdery mildew, aphids, borers, lacebugs, leafhoppers, mealybugs, mites, nematodes, scale, thrips and whitefly. A healthy plant in the proper environment with proper care should have limited problems, however.
Uses
Mass, group or specimen. Shrub borders, mixed borders, woodland gardens, woodland margins, and shade gardens. Informal hedge. Also effective in foundation plantings and as a specimen around the home.