Rhododendron viscosum (Swamp Azalea)

Rhododendron viscosum, commonly referred to as Swamp Azalea, stands as a treasure recognized for both its aromatic blossoms and stunning autumnal foliage. Hailing from the swamps of the eastern United States, spanning from Maine to Alabama and extending westward to Texas, this captivating native plant has captured the hearts of many. Its presence graces gardens with a bushy, deciduous medium-sized shrub that boasts funnel-shaped white flowers, often delicately tinged with hints of pink. These exquisite blooms, characterized by their elongated slender tubes, cluster in groups of 3 to 12. Their profusion delights the senses in early summer, emanating a powerful clove-like fragrance. As the leaves emerge, the flowers grace the landscape with their charm.

Rhododendron Viscosum (swamp Azalea)
  • The allure of Swamp Azalea extends beyond its floral display. Its lustrous dark green leaves, elliptical in shape, transform into a captivating blend of autumnal shades—ranging from vibrant yellows to oranges and purples—offering a spectacular show of colors as fall takes hold. This late-season Azalea is impressively cold-hardy, resilient enough to withstand temperatures as frigid as -20°F (-29°C).
  • With a growth habit that is loose, upright, and spreading, Swamp Azalea can attain heights of 5 to 8 feet (150-240 cm) and spans of 7 to 10 feet wide (210-300 cm). Its tendency to slowly naturalize through root suckers further enriches its impact on the landscape.
  • As a recipient of the prestigious Award of Garden Merit from the Royal Horticultural Society, Swamp Azalea commands admiration and respect.
  • This plant thrives within sun to part shade conditions and flourishes in moist, acidic, humus-rich, and well-drained soils. It exhibits a remarkable tolerance for wet soils, including those with poor drainage, although prolonged submersion is not suitable. For optimal growth, partial shade or dappled sunlight is preferred, as full sun can lead to leaf scorching unless soils remain consistently moist. When planting, take care to position it where it is shielded from harsh winter winds. Frost protection is advised to safeguard the delicate flowers. Annual mulching with leaf mold aids in moisture retention, weed control, and soil cooling.
  • Swamp Azalea is an ideal choice for shrub borders, mixed borders, and shade gardens, exuding elegance wherever it finds a home. The plant’s attractiveness extends beyond humans, attracting butterflies, hummingbirds, and birds.
  • To encourage new growth, remove spent flowers. However, it’s important to note that all parts of the plant are toxic if ingested, making it toxic to dogs, cats, and horses.
  • Swamp Azalea stands as a testament to the beauty and complexity of nature, gracing landscapes with its fragrant blossoms and captivating foliage.