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Swamp Azalea, Swamp Honeysuckle, Clammy Azalea
Rhododendron viscosum

Family: Ericaceae (er-ek-AY-see-ee) (Info)
Genus: Rhododendron (roh-do-DEN-dron) (Info)
Species: viscosum (vis-KOH-sum) (Info)
Synonym:Azalea serrulata
Synonym:Azalea viscosa
Synonym:Rhododendron coryi
Synonym:Rhododendron serrulatum
Synonym:Rhododendron viscosum var. glaucum
» View all varieties of Azaleas and Rhododendrons




4-6 ft. (1.2-1.8 m)

6-8 ft. (1.8-2.4 m)

8-10 ft. (2.4-3 m)


4-6 ft. (1.2-1.8 m)


USDA Zone 4a: to -34.4 C (-30 F)

USDA Zone 4b: to -31.6 C (-25 F)

USDA Zone 5a: to -28.8 C (-20 F)

USDA Zone 5b: to -26.1 C (-15 F)

USDA Zone 6a: to -23.3 C (-10 F)

USDA Zone 6b: to -20.5 C (-5 F)

USDA Zone 7a: to -17.7 C (0 F)

USDA Zone 7b: to -14.9 C (5 F)

USDA Zone 8a: to -12.2 C (10 F)

USDA Zone 8b: to -9.4 C (15 F)

Sun Exposure:

Light Shade


Parts of plant are poisonous if ingested

Bloom Color:


Bright Yellow

White/Near White

Bloom Time:

Late Winter/Early Spring

Mid Spring

Late Spring/Early Summer



Other details:

Flowers are fragrant

Requires consistently moist soil; do not let dry out between waterings

Patent Information:


Seed Collecting:

Allow pods to dry on plant; break open to collect seeds


This plant has been said to grow in the following regions:

Cordele, Georgia

Marietta, Georgia

Coushatta, Louisiana

Pasadena, Maryland

Granville, Massachusetts

Mashpee, Massachusetts

Roslindale, Massachusetts

Closter, New Jersey

Murrysville, Pennsylvania

Pottstown, Pennsylvania

West Chester, Pennsylvania

Conway, South Carolina

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Gardeners' Notes:


On Dec 30, 2014, coriaceous from ROSLINDALE, MA wrote:

This is one of the latest of our native deciduous azaleas to bloom, in early July here (Boston Z6a). Flowers are usually white, rarely pink, yellow in one cultivar, and have a strong clove scent.

In the wild this grows in wet lowlands and swamps. It is very sensitive to drought. All azaleas/rhododendrons have shallow roots that appreciate mulching for moisture retention in the garden, but that goes double for this species. This is a great shrub for natural woodlands. Like other azaleas, it needs acid soil.


On Jan 13, 2014, SoooSirius from Municipality of Murrysville, PA wrote:

Very fragrant, and yes, the stems and buds are sticky. (viscosum)


On Apr 12, 2008, Cordeledawg from Cordele, GA (Zone 8a) wrote:

I recently purchased R. viscosum 'Summer Eyelet' which blooms later than most native azaleas, June/July. I'm trying to decide where to plant this one. It needs to stay moist.


On Jun 11, 2006, struckcheon from Closter, NJ wrote:

Got some this year. Flowers are a beautiful white, very nice form, and they are indeed fragrant. Good for a partially shaded, moist location.