Rhododendron austrinum
Common Name(s):
- Phonetic Spelling
- rho-doh-DEN-dron aw-STRIH-num
- This plant has high severity poison characteristics.
- See below
- Description
-
Florida azalea is an erect, woody, deciduous shrub in the Ericaceae (blueberry) family that will grow 8 to 10 feet tall and wide. It is native to the lower southeastern United States, which does not include North Carolina. The genus named derives from the Greek words rhodo, which means rose, and dendron, meaning tree.
Give this plant partial shade in moist, well-drained, acidic soil and protect it from afternoon sun, which can scorch the leaves. It does not tolerate dense clay, so if you have clay soil, amend with organic material. It will reward you with fragrant flowers plus drought tolerance once established.
The flowers of Florida azalea attract hummingbirds and bees, so place it in a woodland or naturalized area. It may also be grown as a houseplant. Prune rhododendrons and azaleas after they bloom to preserve the current season's bloom, and allow time for the plant to produce flower buds for next year's bloom. Rhododendrons and azaleas set next year's flower buds by mid to late summer.
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 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.
The Clemson Cooperative Extension Home and Garden Information Center has a factsheet on common diseases of rhododendron.
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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- 'Don's Variegated'
- 'Firecracker'
- 'Lisa's Gold'
- 'Don's Variegated'
- 'Don's Variegated', 'Firecracker', 'Lisa's Gold'
- Tags:
- Cultivars / Varieties:
-
- 'Don's Variegated'
- 'Firecracker'
- 'Lisa's Gold'
- 'Don's Variegated'
- 'Don's Variegated', 'Firecracker', 'Lisa's Gold'
- Tags:
-
-
Attributes:
- Genus:
- Rhododendron
- Species:
- austrinum
- Family:
- Ericaceae
- Life Cycle:
- Woody
- Country Or Region Of Origin:
- lower southeastern US
- Wildlife Value:
- Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli.
- Dimensions:
- Height: 8 ft. 0 in. - 10 ft. 0 in.
- Width: 8 ft. 0 in. - 10 ft. 0 in.
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-
Whole Plant Traits:
- Plant Type:
- Poisonous
- Shrub
- Woody Plant Leaf Characteristics:
- Deciduous
- Habit/Form:
- Erect
- Maintenance:
- Low
- Texture:
- Medium
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-
Cultural Conditions:
- Light:
- 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)
- Neutral (6.0-8.0)
- Soil Drainage:
- Good Drainage
- Moist
- Available Space To Plant:
- 6-feet-12 feet
- NC Region:
- Coastal
- Piedmont
- USDA Plant Hardiness Zone:
- 7a, 7b, 8a, 8b, 9a, 9b
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Fruit:
- Fruit Type:
- Capsule
- Fruit Description:
- Elongated capsule
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-
Flowers:
- Flower Color:
- Cream/Tan
- Gold/Yellow
- Orange
- Flower Inflorescence:
- Raceme
- Flower Value To Gardener:
- Fragrant
- Showy
- Flower Bloom Time:
- Spring
- Flower Shape:
- Funnel
- Flower Petals:
- 4-5 petals/rays
- Flower Description:
- Clear yellow, cream, gold-orange to almost red flowers in spring before leaves emerge
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-
Leaves:
- Woody Plant Leaf Characteristics:
- Deciduous
- Leaf Color:
- Gold/Yellow
- Green
- Orange
- Deciduous Leaf Fall Color:
- Brown/Copper
- Gold/Yellow
- Orange
- Leaf Type:
- Simple
- Leaf Arrangement:
- Alternate
- Hairs Present:
- No
- Leaf Description:
- Alternate, simple dark green leaves; yellow to bronze-orange fall color
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-
Stem:
- Stem Is Aromatic:
- No
-
-
Landscape:
- Landscape Location:
- Houseplants
- Naturalized Area
- Woodland
- Design Feature:
- Small groups
- Specimen
- Attracts:
- Bees
- Hummingbirds
- Specialized Bees
- Resistance To Challenges:
- Drought
- Problems:
- Poisonous to Humans
- Problem for Cats
- Problem for Dogs
- Problem for Horses
-
-
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, cardiac failure, difficult breathing, progressive paralysis of arms and legs, coma.
- Poison Toxic Principle:
- Andromedotoxin, Grayantoxin
- Causes Contact Dermatitis:
- No
- Poison Part:
- Bark
- Flowers
- Fruits
- Leaves
- Roots
- Seeds
- Stems