A member of the Rhododendron family, azaleas are a genus of flowering plant, of which there are over 6,000 varieties, according to the Azalea Society of America. Azaleas originated in Asia but are commonly cultivated in American gardens because of their hardiness and attractive blooms. Azalea varieties come in many sizes, including dwarf plants that reach maximum heights of 6 feet or less.
The Rhododendron atlanticum is typically referred to simply as the dwarf or coastal azalea. The plant has escaped cultivation to grow wild in the states of Delaware, Georgia, Maryland, New Jersey, North Carolina, Pennsylvania, South Carolina and Virginia, according to the U.S. Department of Agriculture. Coastal azaleas reach average heights and widths of 3 to 6 feet. The flowers of the Rhododendron atlanticum are white to pink in colour and bloom in mid-April.
Kurume hybrids are a group of dwarf azaleas that get their name from their place of origin, Kurume, Japan. The blossoms of the Kurume hybrids come in a variety of colours, including pink, white, red, salmon, orange, violet and white. The flowers grow in dense bunches, typically obscuring the foliage. Kurume hybrids are evergreen, meaning they retain their leaves throughout the year. The average heights of the Kurume hybrids are 2 to 3 feet, according to the University of Georgia. Over 10 varieties of Kurume are available, including 'Delaware Valley,' 'Sherwood Red,' 'Hinodegiri' and 'Christmas Cheer.'
Another evergreen plant, the Rhododendron eriocarpum or gumpo dwarf azalea reaches heights of only 1 to 2 feet. The gumpo azalea is commonly planted as ground cover and comes in white and pink varieties. Both types bloom in June and July and produce flowers that are 2-1/2 to 3 inches in diameter. Preferring areas with partial shade, the gumpo azalea is hardy to temperatures as low as --12.2 to -20.5 degrees C.
The satsuki hybrid is a class of scientifically-developed dwarf azaleas imported from Japan in 1938, according to North Carolina State University Extension horticultural specialists. The group of flowers takes its name from the Japanese word for the fifth month in the lunar calendar and is meant to indicate the bloom season of the plants--May, June and July. Satsuki hybrids typically reach average heights and widths of 2 to 4 feet. Over 100 varieties of the hybrids exist with flowers varying greatly from type to type. Possible colours include white and various shades of orange, red, pink, purple, and blossoms may feature one colour, two colours or stripes or bands of colouring. Some popular varieties of Satsuki hybrids are the 'Beni-kirishima,' 'Eiten,' 'Higasa' and 'Gunrei.'