Plant Patent #9,981. Rhododendron 'Purple Passion' is a glorious compact bush that offers color and style in the garden. Dark green foliage and intense purple blossoms with a touch of white attract hummingbirds, butterflies and human admirers. The upright evergreen foliage compliments the garden all year long with the promise of a profusion of purple blossoms in the spring. With a height and width of four to five feet, this compact plant is easy to care for in a sunny or partly shady location. Although it can adapt to drought conditions and poor soil, Rhododendron 'Purple Passion' prefers moist, loamy soil. It is disease resistant and requires no maintenance, and it is cold hardy in most cold winter climates in USDA Zones 5 to 8.