Azalea viscosa (syn. Rhododendron viscosum) swamp azalea

Swamp azaleas are a unique species of deciduous azalea of North American origin. These azaleas offer later flowering and extremely fragrant flowers. Their colour is usually white to pale pink, however, some specimens may bloom much richer pink. Those are often categorized as subspecies or they receive variety names. Flowers open in early June and continue flowering for about 3 weeks. Their strong fragrance is notable from a distance of several meters and is lovely and sweet.

Deciduous leaves are smaller than on other deciduous azaleas, broadly elliptic, and fresh green until autumn. Plants form compact and dense, broadly egg-shaped shrubs. Swamp azalea was first described by Karl Linné in 1748, and is thought to have been in cultivation since 1680.

Swamp azaleas love damp soil and plenty of sun. The roots are shallow, spreading to sides in search for nutrients. Never plant them too deep. The soil has to be acidic (pH 4.5-5.5), rich in humus, cool and always moist. Ideal soil mixture is peat with lime-free, light garden soil topped with leaf-mould. For richer flowering and growth dead-head where possible. Hardy to about -29°C (USDA zone 5).

Last update 08-03-2018