Azalea

(Rhododendron species)

August 1996

Summary:

Foliage: Evergreen broadleaf
Height: 6 to 8 feet
Spread: 6 to 8 feet
Shape: Bushy

Small, evergreen leaves are dark green. Clusters of funnel-shaped flowers cover the plant in spring, and are white, pink, red, or purple.

Plant Needs:

Zone: 7 to 9
Light: Partial shade
Moisture: Moist
Soil Type: Sandy to loam
pH Range: 3.7 to 5.5

Functions:

Suggested uses for this plant include massing, border, and specimen plant.

Planting Notes:

Take care in choosing plant location and in soil preparation.
Plant in well-drained, acid soil.
If drainage is a problem, plant in raised beds, or install drainage tile to drain water away from plants.

Care:

Spread a good, organic mulch to control weeds and protect tender shallow roots.
To maintain form and size, pinch off soft, new shoots of vigorous growing plants in spring.
Do not pinch after July. Flower buds won't have time to develop before cold weather.

Problems:

Iron chlorosis (leaves turn yellow between veins, but veins remain green) is a problem in high pH soils.
Some common insect problems are the azalea lacebug, aphids, leaf miners and tiers, scale insects, and whitefly.
Common diseases are Phytophthora root and crown rot, Ovulinia petal blight and powdery mildew.

Alternatives:

Consult local sources, including historic or public gardens and arboreta, regarding cultivars and related species that grow well in your area.

Kurume Azaleas:

`Pink Pearl' has pink flowers.
`Flame' has orange-red flowers with a dark blotch.
`Snow' is the most reliable of the white- flowered Kurume hybrids.

Girard Azaleas:

`Girard's Scarlet' is a low-growing azalea with red flowers.

Comments:

Azaleas usually refer to the native deciduous and hybrid evergreen types with small leaves and funnel-shaped flowers. Rhododendrons refer to the large leaf types with large terminal flower clusters.
Flowering time varies. By combining early, mid-season, and late bloomers, the seasonal show can be extended dramatically.

Additional Materials:

The PRUNING SERIES videotape can be ordered through your local Extension office.
The following Extension publication may be ordered from your local Extension office, or directly from: Extension Distribution Center 112 Landsdowne Street Blacksburg, VA 24061
#426-602 "Growing Azaleas and Rhododendrons"
#426-500 "Winter Injury to Trees and Shrubs"
#426-607 "Selecting Landscape Plants - Broad-leaved Evergreens"

This material was developed by Carol Ness as part of the Interactive Design and Development Project funded by the Kellogg Foundation. Mary Miller, Project Director. Diane Relf, Content Specialist, Horticulture. Copyright 1989 by VCE.

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