Rhododendron Species, Royal Azalea

This is arguably the most beautiful of the east Asian azaleas. When it's in bloom, photographers and Korean wedding parties flock to the ...Read Moremass plantings at the Arnold Arboretum. On seed-grown plants, the flower color varies agreeably, most commonly shell pink but ranging from white to medium pink.

But this is a beautiful plant in or out of bloom. The branching architecture is good. The foliage is attractive, with relatively large leaves mostly in pseudo-whorls at the ends of the branchlets, appearing with the flowers. The leaves are deciduous, and fall color is often excellent, ranging from yellow to crimson.

This isn't the easiest of azaleas to cultivate. It can be slow to establish and slow to grow, and its botanical name is the subject of jokes among azalea fanciers, as its health is often schlippin' back. If it grows senescent after a decade, it can be renewal pruned by cutting it to the ground. It requires good drainage and prefers a higher soil pH than most azaleas. Its foliage is subject to sunburn when exposed to afternoon sun.

Generally considered hardy in Z4a. It's not very heat tolerant, and on the east coast of N. America it's not thrifty much south of Z6. Michael Dirr has tried and failed several times with this in Athens, GA (Z7b).

This is probably the best of the Far East Azaleas; certainly it is the hardiest (zone 5a). They flower just as the leaves emerge with bl...Read Moreooms pale to rose pink. The leaves are produced in whorls of five and each leav is shaped like those of an english oak. Very attractive all season. Good fall colour as well. Closely related to the Japanese Azaleas, the Royal Azalea is native to Korea and NE Manchuria. Although it may reach 15 feet, in open, sunny areas they usually stay under 5 feet. An excellent addition to any ericaceous planting.