|R. yedoense, the Yodogawa Azalea, is native to Korea and has been cultivated in Japan for hundreds of years. A medium evergreen shrub, this species has sterile flowers and must be propagated vegetatively. Its double flowers are light purple and fragrant and are longer-lasting than the single flowers. It is usually very hardy but is often semi-evergreen to deciduous in colder climates.
Though azaleas have a potentially large list of possible pest and disease problems, they are usually trouble free if planted correctly in proper cultural conditions.