Clammy Azalea
Rhododendron viscosum
Last reviewed: June 2026
Rhododendron viscosum (Clammy Azalea) is a deciduous shrub native to eastern North America that produces fragrant white flowers in June and July. This moisture-loving plant thrives in partial shade and attracts bees, butterflies, and hummingbirds.
Clammy Azalea is toxic to dogs and cats.
Listed as toxic by the ASPCA Animal Poison Control Center (opens in new tab) (last reviewed 2026-05-21). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435and your veterinarian's emergency line.
Pollinator Patch flags toxic plants so you can choose a pet-safe native alternative for your yard.
The USDA PLANTS Database (opens in new tab) does not flag Clammy Azalea as toxic to livestock.
Light
part shade
Water
high
Size
36"–120" H × 36"–96" W
Bloom
Jun, Jul
Native to
AL, AR, CT, DE and 19 more states
Pollinators
bees, butterflies, hummingbirds
Clammy azalea is a native deciduous shrub that produces clusters of fragrant white or pink tubular flowers in early summer. This moisture-loving plant thrives in partially shaded areas and can reach 3-10 feet tall and wide at maturity. It prefers consistently moist soil and provides excellent seasonal interest with its showy blooms.
Growing Clammy Azalea
Grow Clammy Azalea in part shade and high water. Mature plants reach 36 to 120 inches tall and spread 36 to 96 inches wide. Expect moderate maintenance to keep it looking intentional in a front yard.
In an HOA neighborhood
Clammy Azalea is an HOA-friendly choice. Maintenance level: moderate. Tidiness: 4 out of 5.
Works well in: front yard, foundation, mid zone.
- Requires consistent moisture to maintain appearance
- Can become leggy without proper pruning
Wildlife value
Host plant for Azalea sphinx moth.
The fragrant flowers attract bees, butterflies, and hummingbirds during the June-July bloom period. This native azalea serves as an important nectar source for pollinators during the summer months.
Common questions
- When does Clammy Azalea bloom?
- Rhododendron viscosum blooms in June and July, producing clusters of fragrant white tubular flowers.
- What pollinators visit Clammy Azalea?
- Clammy Azalea attracts bees, butterflies, and hummingbirds with its fragrant nectar-rich flowers.
- Where is Rhododendron viscosum native?
- Clammy Azalea is native to 24 states across eastern North America, from Maine south to Florida and west to Texas and Oklahoma.
- What growing conditions does Clammy Azalea prefer?
- This shrub thrives in partial shade to shade with consistently moist to wet soil conditions, making it ideal for woodland gardens and wet areas.
- Is Clammy Azalea toxic to dogs?
- Yes. Clammy Azalea is listed as toxic to dogs by the ASPCA Animal Poison Control Center (aspca.org). If your pet has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Clammy Azalea toxic to cats?
- Yes. Clammy Azalea is listed as toxic to cats by the ASPCA Animal Poison Control Center (aspca.org). If your cat has been exposed, call the ASPCA Animal Poison Control Center at (888) 426-4435.
- Is Clammy Azalea toxic to livestock?
- The USDA PLANTS Database does not flag Clammy Azalea as toxic to livestock.
- Is Clammy Azalea HOA-friendly?
- Clammy Azalea is generally an HOA-friendly choice in the right placement, with moderate maintenance.
Native range data from the USDA PLANTS Database and regional native plant society lists. Pollinator and host plant associations compiled from GBIF, iNaturalist, and published ecological literature.
Pollinator Patch flags toxic plants like Clammy Azalea and shows pet-safe natives for your ecoregion instead.
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