Rhododendron is a large genus, which includes rhododendrons and azaleas, of more than 1,000 species of shrubs and small trees in the family Ericaceae. Prized for their glossy foliage and showy clusters of blooms, Rhododendron spp. may be evergreen or deciduous and grow in a wide range of conditions. Hybridization has resulted in thousands of cultivars with various foliage and flower characteristics, as well as improved hardiness. There are rhododendrons and azaleas for just about every landscape situation. Rhododendrons have many potential disease and insect problems, including root rot, powdery mildew, rust, petal blight, lace bugs, Japanese beetle and vine weevil.