Difference between Azalea and Rhododendrons
The plants we call azaleas and rhododenÂdrons all belong to the Ericaceae family, as do heathers and the strawberry tree. Most of them prefer acid soils. At one time, azaleas were treated as a distinct genus, but they are now. botanically speaking, all considered to be forms of rhododendron.
Image Credit: Wiki
Perhaps the most important gardening disÂtinction between the hardy types is that most rhododendrons require greater shade than do most azaleas. This should be borne in mind when planting a mixed shrubbery.
Image Credit: Wiki