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Rosebay Rhododendron

Other Common Name(s):

Other plants called Rosebay:

Phonetic Spelling
rho-doh-DEN-dron
This plant has high severity poison characteristics.
See below
Description

Azaleas and rhododendrons are woody, evergreen or deciduous, rounded  shrubs in the Ericaceae (blueberry) family. They are native to the United States and Asia and there are many cultivars and varieties, some native to North Carolina. They typically grow 6 to 10 feet tall and 5 to 8 feet wide. The genus name derives from the Greek words rhodo, which means rose, and dendron, meaning tree.

These plants prefer moist, well-drained, acidic soils in dappled shade and protection from afternoon sun which can scorch the leaves. They do not tolerate dense clay, so if you have clay soil, amend with organic material. The roots may rot if soil does not drain well. Plant the root ball high in the soil to help with drainage issues. Avoid overwatering and over-fertilizing. Pruning, if desired, may be done after flowering. 

Azaleas and rhododendrons are at home as understory shrubs planted in groups in woodland or naturalized areas, or as specimens in pollinator gardens where the flowers will attract hummingbirds and bees. Some varieties are grown as houseplants. 

Insects, Diseases, and Other Plant 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. 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 listed in the left-hand sidebar.

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 landscapes:
Wild Side- A Shady Garden Woodland Walk Wild Side- A Shady Garden Woodland Backyard Garden Walk Juniper Level Botanic Gardens: Part Sun-Part Shade Gardens Woodland Walk Juniper Level Botanic Gardens: Front Shade Garden Woodland Backyard Garden Walk Juniper Level Botanic Gardens: Part Sun-Part Shade Gardens Flower Bonanza Garden Woodland Backyard Garden Walk Juniper Level Botanic Gardens: Front Shade Garden Woodland Backyard Garden Walk Back of House Planting Flower Bonanza Garden Woodland Walk Coastal Entryway Garden Rock & Water Garden
Cultivars / Varieties:
'Aubie', 'Dr. A. Blok', Encore® Series, 'Girard's Crimson', 'Golfer', 'Graziella', 'High Tide', 'Knaphill and Exbury Azaleas', 'Maximum', 'Nancy of Robin Hill', Pale Moon, PJM Group, R. alabamense, 'Ramapo', R. arborescens, R. atlanticum, R. austrinum, R. calensulaceum, R. canescens, R. catawbiense, R. cumberlandense, R. eriocarpum, R. flammeum, R. impeditum, R. indicum, R. kaempferi, R. maximum, R. minus, R. mucronulatum, 'Roseum-Elegans', R. periclymenoides, R. ponticum, R. prunifolium, R. roseum, R. schlippenbachii, R. vaseyi, R. viscosum, R. yakushimanum, 'Silver Bear', Southern Indica Hybrids, 'Strawberry Ice', 'Windbeam', x bakeri 'Clyo Red', x hybridum 'Glenn Dale', x hybridum 'Gunrei Satzuki', x 'Stonewall Jackson'
Tags:
#evergreen#showy flowers#deciduous#houseplant#specimen#slow growing#nectar plant#native bees#woody#low maintenance#tsc#dappled shade#specialized bees#cpp#deer browsing plant#naturalizes#screening#pollinator plant#leathery leaves#understory planting#understory shrub#problem for cats#tsc-s#problem for dogs#bee friendly#problem for horses#shrub borders#woodland garden#container plant#woodland
 
Cultivars / Varieties:
'Aubie', 'Dr. A. Blok', Encore® Series, 'Girard's Crimson', 'Golfer', 'Graziella', 'High Tide', 'Knaphill and Exbury Azaleas', 'Maximum', 'Nancy of Robin Hill', Pale Moon, PJM Group, R. alabamense, 'Ramapo', R. arborescens, R. atlanticum, R. austrinum, R. calensulaceum, R. canescens, R. catawbiense, R. cumberlandense, R. eriocarpum, R. flammeum, R. impeditum, R. indicum, R. kaempferi, R. maximum, R. minus, R. mucronulatum, 'Roseum-Elegans', R. periclymenoides, R. ponticum, R. prunifolium, R. roseum, R. schlippenbachii, R. vaseyi, R. viscosum, R. yakushimanum, 'Silver Bear', Southern Indica Hybrids, 'Strawberry Ice', 'Windbeam', x bakeri 'Clyo Red', x hybridum 'Glenn Dale', x hybridum 'Gunrei Satzuki', x 'Stonewall Jackson'
Tags:
#evergreen#showy flowers#deciduous#houseplant#specimen#slow growing#nectar plant#native bees#woody#low maintenance#tsc#dappled shade#specialized bees#cpp#deer browsing plant#naturalizes#screening#pollinator plant#leathery leaves#understory planting#understory shrub#problem for cats#tsc-s#problem for dogs#bee friendly#problem for horses#shrub borders#woodland garden#container plant#woodland
  • Attributes:
    Genus:
    Rhododendron
    Family:
    Ericaceae
    Life Cycle:
    Woody
    Country Or Region Of Origin:
    USA, NC, Asia
    Wildlife Value:
    Flowers attract humingbirds. Members of the genus Rhododendron support the following specialized bee: Andrena (Andrena) cornelli. Deer browse this plant.
    Dimensions:
    Height: 2 ft. 0 in. - 25 ft. 0 in.
    Width: 2 ft. 0 in. - 25 ft. 0 in.
  • Whole Plant Traits:
    Plant Type:
    Poisonous
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Deciduous
    Habit/Form:
    Rounded
    Growth Rate:
    Slow
    Maintenance:
    Low
  • Cultural Conditions:
    Light:
    Dappled Sunlight (Shade through upper canopy all day)
    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)
    Soil Drainage:
    Good Drainage
    Moist
    Available Space To Plant:
    12 inches-3 feet
    3 feet-6 feet
    6-feet-12 feet
    12-24 feet
    NC Region:
    Coastal
    Mountains
    Piedmont
    USDA Plant Hardiness Zone:
    6b, 6a, 7b, 7a, 8b, 8a
  • Fruit:
    Fruit Color:
    Brown/Copper
    Red/Burgundy
    Display/Harvest Time:
    Fall
    Fruit Type:
    Capsule
    Fruit Length:
    < 1 inch
    Fruit Description:
    Dry red-brown capsule 1/2" long appearing in fall
  • Flowers:
    Flower Color:
    Gold/Yellow
    Orange
    Pink
    Purple/Lavender
    Red/Burgundy
    White
    Flower Inflorescence:
    Raceme
    Flower Value To Gardener:
    Fragrant
    Showy
    Flower Bloom Time:
    Spring
    Flower Shape:
    Bell
    Funnel
    Flower Petals:
    4-5 petals/rays
    Flower Size:
    1-3 inches
    Flower Description:
    2 1/2 inches wide, bell or funnel shaped with 5 petals in various colors bloom in April or May
  • Leaves:
    Woody Plant Leaf Characteristics:
    Broadleaf Evergreen
    Deciduous
    Leaf Color:
    Green
    Leaf Feel:
    Glossy
    Leathery
    Leaf Type:
    Simple
    Leaf Arrangement:
    Alternate
    Leaf Shape:
    Elliptical
    Lanceolate
    Oblanceolate
    Leaf Margin:
    Entire
    Hairs Present:
    Yes
    Leaf Length:
    3-6 inches
    Leaf Width:
    1-3 inches
  • Stem:
    Stem Color:
    Gold/Yellow
    Gray/Silver
    Stem Is Aromatic:
    No
    Stem Description:
    Leaf buds are small, flower buds are larger and shaped like eggs, gray to yellowish
  • Landscape:
    Landscape Location:
    Naturalized Area
    Woodland
    Design Feature:
    Border
    Mass Planting
    Screen/Privacy
    Small groups
    Specimen
    Attracts:
    Hummingbirds
    Pollinators
    Specialized Bees
    Problems:
    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, difficult breathing, progressive paralysis of arms and legs, cardiac failure, coma.
    Poison Toxic Principle:
    Andromedotoxin, Grayantoxin
    Causes Contact Dermatitis:
    No
    Poison Part:
    Bark
    Flowers
    Fruits
    Leaves
    Roots
    Sap/Juice
    Seeds
    Stems