A Technical Report from The Bartlett Tree Research Laboratories
Azalea and rhododendron, combined in a single genus, Rhododendron, are the most popular plants used in the landscape. The genus represents 800 to 900 species of evergreen, semievergreen, and deciduous plants and many thousands of cultivated varieties. These shrubs display a wide diversity of flower color, foliage traits, growth habits, and flowering dates.