Evergreen Azaleas

The most impressive flowering shrub in the U.S. Northeast and the Northwest is the rhododendron, and the most stunning flowering shrub of the U.S. Southeast, Gulf Coast and Southern California is the evergreen azalea. Neither survives happily in the central U.S. Azaleas, including evergreen azaleas, are members of the rhododendron genus. The basic difference between azaleas and other rhododendrons is that azalea flowers have five pollen-bearing stamens while rhododendrons have 10 or more. The exceptions are R. canadense and R. vaseyi which have from 7 to 10 stamens. Azaleas are among the most colorful of all flowering shrubs, bearing 3 to 6 in. (8 to 15 cm) clusters of red, yellow, orange, pink, white or purple flowers in spring and early summer, and, in many cases, provide brilliantly hued leaves in fall. Evergreen azaleas are widely grown from Zone 6 south. Many nursery catalogues list azaleas separately from rhododendrons, but both belong to a single genus, Rhododendron. Azaleas will serve most garden uses admirably, and they also can be grown in open woodlands in light shade where, with proper initial soil preparation, they are often able to take care of themselves indefinitely.

All approximately 45 evergreen azalea species are in the subgenera Azaleastrum and are native to Asia. Of these, species of Section Tsutsusi (evergreen azaleas) occur only in southeastern Asia. They are most numerous in Japan, with some species in southeastern China, Korea, the Philippines and in Taiwan. Many appear to be evergreen because they are dimorphic, that is they grow two sets of leaves each year. Dimorphic evergreen azaleas have spring leaves and summer leaves. The spring leaves unfold at the beginning of the growing season and are dropped in autumn. Summer leaves emerge in early summer and are smaller, thicker, darker, and more leathery than spring leaves. They remain on the plant during the dormant period and drop in the spring, however, summer leaves may persist for several years in warm climates and may drop before spring in cold climates. The latter is called being semievergreen or semipersistent.

Evergreen azaleas began to be established in cultivation in Europe in the early 1800's. The first ones were not hardy and were used for greenhouse and indoor decoration, and are known as Indian or Belgian Indian Hybrids. The name "Indian" was derived from a misidentification of Rhododendron indicum as being associated with this group. A mixed group developed in the southern US beginning in the middle of the 1800's, in part from the Belgian Indian types, is known as Southern Indian Hybrids. A large group of evergreen azaleas, known as Kurume Hybrids, has its origin near the Japanese city of Kurume. They became widely known in the West through the work and writing of E.H. Wilson, who selected and imported 50 cultivars from Japan, arriving at Arnold Arboretum in Boston 1919. The new summer blooming Encore Azaleas are related to the Kurume azaleas. Similar to the Encore Azaleas are the Bloom-A-Thon® Azaleas and ReBLOOM® Azaleas® introduced by Bob Head. A third major group is the Kaempferi Azaleas, derived in part from Rhododendron kaempferi and developed in Holland after World War I. Another group, the Satsuki Azaleas, is highly prized in Japan and has been used by hybridizers in the West. The North Tisbury hybrids were introduced by Poly Hill of Martha's Vineyard from seed she received from Japan from the Formosan azalea R. nakaharai starting in 1965.

The Inter-Group Evergreen Azalea Hybrids include relatively new groups of hybrid azaleas that have been derived from plants in several groups, such as Satsuki, Kaempferi, and Kurume. The popular Glenn Dale hybrids are assigned to this group; they were developed, starting in 1935, by B.Y. Morrison in Glenn Dale, Maryland. Back Acre hybrids were also developed by B. Y. Morrison after his retirement to Pass Christian, Mississippi, in 1964, where he continued his azalea breeding work on his farm called Back Acres. In 1950, the USDA in Glenn Dale, Maryland, released the Beltsville hybrids developed by Guy Yerkes and Robert L. Pryor and often called the Yerkes-Pryor hybrids. CARLA hybrids were developed at NC State in conjunction with LSU by Dr. Stadtherr starting in 1965. Robin Hill hybrids were developed in New Jersey, so they are cold hardy. Dr. August Kehr, former geneticist with the U.S. Department of Agriculture, developed some spectacular azalea cultivars having double or semi-double camellia-like flowers. Gable hybrids were introduced by the late Joseph B. Gable, a nurseryman and hybridizer in Stewartstown, Pennsylvania. They are among the hardiest evergreen azaleas. Linwood Hardy hybrids were developed by Al Reid by combining outstanding characteristics of greenhouse plants with hardy azaleas. Pennington hybrids consist of 16 named cultivars developed by the late Ralph Pennington in Covington, Georgia. Harris hybrids were developed by James Harris in Lawrenceville, Georgia. Pericat hybrids were developed by Alphonse Pericat in Collingdale, Pennsylvania, for greenhouse forcing but are as hardy as Kurume hybrids. Aromi hybrids were developed by Dr. Gene Aromi, a retired University of Southern Alabama professor in Mobile, Alabama. Holly Springs hybrids were created by Col. Ronald C. Vines (Ret.) in Springfield, Virginia, just south of Washington DC. Huang hybrids were created by a Mr. Huang in China. Klimavicz hybrids were created by Joe Klimavicz in Vienna, VA.

Most of the rhododendrons and azaleas grown in gardens are hybrids, and their ability to resist cold differs remarkably from one variety to another. For this reason it is best to purchase rhododendrons and azaleas from a local nurseryman who grows his own plants. The descriptions below cover evergreen azaleas that have proven satisfactory in fairly broad regions.

Examples of Evergreen Azalea Species

Examples of Hybrid Evergreen Azaleas

Examples of Evergreen Azalea Species

Evergreen Azalea Species

R. kiusianum, the Kyushu azalea – 3 ft. (1.2 m), -10°F (-23°C). It is a low-growing Japanese species, often only 18 in. (.5 m) high in the wild. Its leaves are deciduous when the plant is young but evergreen in maturity, remaining on the plant all winter, though often changing color. In its original form the Kyushu azalea is covered in mid-spring with 8 to 10 in. (20 to 25 cm) clusters of lilac pink flowers, but there are many named hybrids derived from this species bearing white, pink, rose or purple flowers. It blooms while still young, bearing flowers 1 to 1 1/2 in. (2.5 to 3.8 cm) across. It is hardy in Zone 7, +5°F (-15°C). This semi-evergreen spreading shrub grows 3 ft. (.9 m) tall, but up to 5 ft. (1.5 m) wide. The shiny 1 in. (2.5 cm) leaves sometimes turn red in winter.

R. mucronatum, the Snow azalea – 3 ft. (.9 m), -5°F (-21°C). It has Chinese ancestry but is not found in the wild. It is commonly used for ornamental pruning where it will grow 6 ft. (1.8 m) high and 4 to 6 ft. (1.2 to 1.8 m) wide. It is hardy to Zone 5, -15F (-26°C). Its many branches are densely covered with oval evergreen leaves, 1 1/2 to 2 1/2 in. (3.8 to 6.4 cm) long, matted with hairs. Its fragrant white flowers, 1 to 3 in. (2.5 to 7.6 cm) wide, often bloom in pairs and may be stained with green, lilac or pink at the base, depending on the variety.

R. stenopetalum 'linearifolium' – 4 ft. (1.2 m), -15°F (-26°C). The Spider azalea, is an unusual Japanese species. It is a 4-foot-tall shrub with narrow, ribbon-like evergreen leaves, 3 in. (7.6 cm) long and 1/2 in. (1.3 cm) wide, and rose-pink flowers with deeply divided petals. It is hardy to Zone 5, -15°F (-26°C). In one variety, R. linearifolium 'Macrosepalum', the plant is somewhat smaller, 3 ft. (.9 m) tall, and the leaves are deciduous and 3 in. (7.6 cm) long. But the flowers are even more curiously shaped than those of the species; they have 1 1/4 in. (.6 cm) long sepals that overshadow the petals. The flowers of this variety are fragrant and have been bred in several colors; in one, 'Polypetalum', flower petals and leaves are so similar in size that the plant seems to have pink and green leaves.

R. yedoense, the Yodogawa azalea – 2 ft. (.6 m), -5°F (-21°C). It has 2 in. (5.1 cm) double reddish purple flowers in late spring. Although this plant is technically an evergreen azalea it is deciduous in cold climates. Plants rarely grow more than 3 ft. (.9 m) tall, but may spread to 6 ft. (1.8 m) in diameter. It is hardy in Zone 6 to -5°F (-21°C). The variety R. yedoense 'Poukhanense', Korean Yodogawa azalea, has single flowers and is a bit more resistant to winter cold than the double-flowered type. It is a low, spreading plant that is hardy to -15°F (-26°C). The leaves of both drop in Northern gardens, but remain nearly evergreen in milder climates. [Return to Evergreen Azalea Species Index]

Examples of Hybrid Evergreen Azaleas

Aromi Azaleas by Dr. Gene Aromi of Mobile, AL

The Aromi hybrids were developed by Dr. Gene Aromi, a retired University of Southern Alabama professor, and his wife Jane, a retired elementary school teacher in Mobile, Alabama. They began their hybridizing program in 1969 to develop evergreen azaleas with "large flower size, early bloom time, improved bud hardiness, compact habit, an array of flower forms, and rich colors". They have named 31 evergreen azalea hybrids. Examples include: Sophia, pink with red flair; Amelia Rose, purplish red; Michaele Lux, purplish pink with purplish red blotch; and Katherine Alison, red. They are typically hardy to 0°F (-18°C). [Return to Hybrid Evergreen Azalea Index]

August Kehr Hybrids from MD and NC

August Kehr Hybrids. Dr. August Kehr, former geneticist with the U.S. Department of Agriculture, developed some spectacular azalea cultivars having double or semi-double camellia-like flowers. Cultivars include ´Anna Kehr´, double rosy-pink flowers with wavy edges; ´Mary Lou Kehr´, light pink, semi-double fragrant flowers; ´Great Expectations´, reddish-orange double flowers; and ´White Rosebud´, white double flowers with yellow-green center. The plants are hardy to 0°F (-18°C). [Return to Hybrid Evergreen Azalea Index]

Back Acre Azaleas by Ben Morrison, Pass Christian, MS

Back Acres azaleas were developed by B. Y. Morrison after his retirement to Pass Christian, Mississippi, in 1964. Morrison had developed the Glenn Dale Azaleas while working for the U.S. Department of Agriculture. After retiring he continued his azalea breeding work on his farm called Back Acres. They are hardy to Zone 7, 0°F (-18°C) and may grow upright or spread out; they usually reach 3 to 5 ft. (.9 to 1.5 m) in height after about seven years. Individual blossoms range from 1 1/2 to 3 in. (3.8 to 7.6 cm) across. Of the 50 named varieties the following are recommended: ´Marian Lee´, (white petals with a tint of pink and carmen-red border); ´May Blaine´, (light purple double flowers); 'St. James', brilliant red-orange flowers with a white center; 'Starfire', double deep pink with purplish red dots; 'Theron Perkins, (deep pink to yellowish pink with red margins, double flowers); and ´Debonair´, (vivid pink flowers with deep pink edges and light pink to greenish centers). For hardiness: 'Aphrodite', purplish pink; 'Ben Morrison', salmon-pink; and 'Fashion', rose pink, are hardy to Zone 6, -5°F (-21°C). [Return to Hybrid Evergreen Azalea Index]

Indica or Belgian Indian Azaleas

The Indica or Belgian Indian azaleas are divided into two groups according to their hardiness. The Belgian Indicas were developed as house plants in the 1800s and are generally hardy to Zone 10, +35°F (+2°C); Southern Indicas were developed from plants at Magnolia Plantation in Charleston, S.C. and are generally hardy to Zone 8, +15°F (-9°C). Both types may become 6 ft. (1.8 m) tall and 10 ft. (3 m) or more across after 5 to 10 years in the garden. The flowers, especially of the Belgian Indica type, are apt to be frilled at the edge or many-petaled double blossoms and often are 2 to 3 in. (5.1 to 7.6 cm) across. Typical Belgian Indica varieties are: 'Alaska', snow white, two layers of petals; 'Albert and Elizabeth', white, edged pink, double; 'Avenir', salmon pink, double; 'California Sunset', variegated white and pink, double; and 'Fire Dance', fiery red, double. Typical Southern Indicas, all with single blossoms having one layer of petals, are 'Brilliant', red; 'Duc de Rohan', salmon pink; 'Fielder's White', snow white; 'Lady Cavendish', multi-colored with a pink splotches; 'Prince of Wales', cherry red; ´Formosa´, (deep magenta-purple flowers); ´George Lindley Taber´, (white flowers with purplish-pink blotch and purple throat); ´Delaware Valley White´, (pure white flowers with ruffled petals); 'Formosa', also called 'Phoenicia', lavender; and 'Southern Charm', deep rose pink. For hardiness: Southern Indicas are hardy to about 0°F (-18°C). [Return to Hybrid Evergreen Azalea Index]

Beltsville (Yerkes-Pryor) hybrids by Guy Yerkes & Robert L. Pryor, Beltsville, MD.

Beltsville (Yerkes-Pryor) Hybrids were introduced by the USDA Beltsville Station in Maryland. They were bred for hardiness. Yerkes started the project. Pryor took over later and introduced 19 true genetic dwarf Kurume azaleas. ´Carol´ is a white hose-in-hose. ´Eureka´ is a purplish pink hose-in-hose. ´Guy Yerkes´ is a yellowish pink hose-in-hose with pink specks in throat, ´H.H.Hume´ is white with a yellowish throat and hose-in-hose. They are hardy to 5°F (-15°C). [Return to Hybrid Evergreen Azalea Index]

Bloom-A-Thon® Azaleas by Robert & Lisa Head, Seneca, SC

Bred in Seneca, South Carolina, by Bob Head, Bloom-A-Thon® Azaleas are similar to Encore™ azaleas and are said to bloom for 4-6 weeks in spring, and then another 12-16 weeks in summer and fall. Introduced in Spring 2012, little is known about them. They are patented as are Encore™ azaleas and the Bloom-A-Thon patents compare them to Encore™ azaleas. Bloom-A-Thon® Pink Double is double and the pollen parent is 'Watchet'. Bloom-A-Thon® red is semi-double and the pollen parent is 'September Song'. Bloom-A-Thon® Lavender is single. Bloom-A-Thon® White is single and the pollen parent is 'September Song'. They are all said to be hardy in USDA zones 6-9. [Return to Hybrid Evergreen Azalea Index]

CARLA hybrids Dr. Stadtherr, Raleigh, NC.

CARLA Hybrids were bred at North Carolina State and Louisiana State universities by Dr. Richard J. Stadtherr for resistance to Phytophthora. This breeding program began in 1960 at North Carolina State University. Dr. Stadtherr moved to LSU in 1968 and continued the program there. The goal was to produce greenhouse-forcing azaleas with mostly double flowers that opened simultaneously. This group is also disease-resistant and relatively cold hardy. ´These midseason bloomers include ´Pink Camellia´, a light purplish pink, double, that opens wide with seldom any stamens or pistol, hardy to 5°F (-15°C); deep rose-pink 'Adelaine Pope', hardy to 5°F (-15°C); deep purplish pink double 'Dixie Rose' with no stamens, hardy to 15°F (-9°C); and deep purplish pink semidouble 'Carror' with no stamens, hardy to 5°F (-15°C). [Return to Hybrid Evergreen Azalea Index]

Encore Azaleas™ by Buddy Lee, Independence, LA

Encore Azaleas™ are similar to Kurume azaleas except they are bred to bloom both in the spring on old growth and then again in the summer and fall on new growth. Encore azaleas™ were Bred by Robert E. "Buddy" Lee of Independence, Louisiana, and introduced by Flowerwood Nursery in Mobile, Alabama. They are bred from Rhododendron oldhamii ´Fourth of July´ -- a cultivar selected from seed collected in 1968 at 2,500 ft. (762 m) up Taiwan's Mount Tai Tun. The female parent used to create Autumn Amethyst™ was a winter hardy hybrid called ´Karens,´ a cross between ´Hinodegiri´, the old Kurume variety, and R. yedoense var. poukhanense, the Korean azalea. Lee selected the seedling that was to be named Autumn Amethyst™, 'Conlee', in 1986 but did not receive the plant patent until 1998. Encore azaleas™ are available in an array of colors, growth forms and bloom characteristics. One of the newest cultivars is Autumn Angel™, 'Robleg', the first white flowered fall blooming azalea. Common varieties include Autumn Royalty™, 'Conlec'; Autumn Rouge™, 'Conlea' and Autumn Cheer™, 'Conlef'. There are currently more than 20 varieties. They have primarily been tested in the Southeast US. The hardiest ones are good to Zone 7, +5°F (-15°C) and include: Autumn Amethyst™, 'Conlee'; Autumn Angel™, 'Robleg'; Autumn Belle™, 'Robleo'; Autumn Carnation™, 'Roblec'; Autumn Carnival™, 'Conlet'; Autumn Chiffon™, 'Robled'; Autumn Coral™, 'Conled'; Autumn Debutante™, 'Roblel'; Autumn Embers™, 'Conleb'; Autumn Empress™, 'Conles'; Autumn Monarch™, 'Conleo'; Autumn Moonlight™, 'Robler'; Autumn Princess™, 'Roblea'; Autumn Rouge™, 'Conlea'; Autumn Royalty™, 'Conlec'; Autumn Ruby™, 'Conler'; Autumn Sangria™, 'Roblee'; Autumn Starlite™, 'Roblem'; Autumn Sundance™, 'Roblef'; Autumn Sunset™, 'Roblen'; Autumn Sweetheart™, 'Robleja; and Autumn Twist™, 'Conlep'. [Return to Hybrid Evergreen Azalea Index]

Gable Azaleas by Joe Gable, Stewartstown, OH

Gable azaleas from Joe Gable in Pennsylvania are hardy to Zone 7, -5°F (-21°C). The plants, most of which become 2 to 4 ft. (.6 to 1.2 m) tall in four to six years and have 1 in. (2.5 cm) shiny leaves, bear great numbers of 2 in. (5.1 cm) blossoms in the spring. Typical varieties are 'David Gable', rosy pink; 'Forest Fire', blood red; 'Louise Gable', salmon pink; 'Rosebud', bright pink; 'Rose Greeley', white; and 'Stewartsonian', deep red. For hardiness: 'Herbert', purplish red; 'Purple Splendor', rich purple; and 'Stewartsonian', blood orange; are hardy to Zone 5, -15°F (-26°C). [Return to Hybrid Evergreen Azalea Index]

Girard Azaleas by Peter Girard in Geneva, Ohio

Girard azaleas are a fairly recent introduction among evergreen azaleas suitable for colder climates. Their growth habits vary with variety, but generally most are fairly low and bushy. Leaves are bright green and some develop a reddish fall color. Although some older leaves may drop in the fall, leaf retention is greater than that of the Gable hybrids. Flowers are primarily single, but fairly large. There are many fairly hardy varieties in this group. Here are a few distinctive varieties to consider.

Glenn Dale Azaleas by Ben Morrison, Glenn Dale, MD

Glenn Dale azaleas from Ben Morrison at the U.S. Department of Agriculture Plant Introduction Station in Glenn Dale, Maryland, are hardy to Zone 7, 0°F (-18°C) and may grow upright or spread out; they usually reach 3 to 5 ft. (.9 to 1.5 m) in height after about seven years. Individual blossoms range from 1 1/2 to 3 in. (3.8 to 7.6 cm) across. Of the 450 named varieties the following are recommended: 'Aphrodite', pale rose pink; 'Aviator', (white with pink flecks); 'Buccaneer', orange red; 'Cavalier', orange red; 'Everest', white with chartreuse blotch; 'Geisha', white striped red; 'Glacier', white; 'Greeting', (red); 'Nocturne', (purplish red with orangish throats); 'Paladin', (purple); ´Zulu´, (vivid purple flowers with dark blotch); ´Cinderella´, (white and red flowers or white stripped with red); ´Ambrosia´, (deep yellow-pink flowers); ´Sagittarius´ (vivid pink flowers with orange undertones); and 'Vestal', white with chartreuse blotch. For hardiness: 'Aphrodite', purplish pink; and 'Fashion', rose pink, are hardy to Zone 6, -5°F (-21°C). [Return to Hybrid Evergreen Azalea Index]

Harris Azaleas by James Harris of Lawrenceville, GA

Harris hybrids were developed by James Harris in Lawrenceville, Georgia. Several cultivars have large vivid-red flowers with light-colored centers and dark margins. Some have a cascading growth habit and are excellent for hanging basket culture. Most bloom mid-season. ´Bryan Harris´, pink with a light center, is one of the popular cultivars. Others include ´Fascination´, single pinkish-white flowers with deep-red borders; 'Joan Garrett', (pale pink with red spotting); ´Parfait´, pastel pink flowers with red dots; and ´Midnight Flare™, single, deep red flowers with wavy edges. They are hardy to at least 0°F (-18°C). [Return to Hybrid Evergreen Azalea Index]

Holly Springs Azaleas by Col. Ronald C. Vines of Springfield, VA

The Holly Springs hybrids were created by Col. Ronald C. Vines (Ret.) in Springfield, Virginia just south of Washington DC. Col. Vines ("Pete") started his hybridizing program in 1977 "to produce azaleas with larger blooms, dwarf to mid-size growth habit and increased cold hardiness". They are hardy to 0°F (-18°C). [Return to Hybrid Evergreen Azalea Index]

Huang Azaleas by Mr. Huang of China

The Huang hybrids were created by Mr. Huang in China before their Cultural Revolution. Col. Vines ("Pete") feels the Huang hybrids may be the most important hybrid group of evergreen azaleas in existence, in terms of the diverse bloom size and type, foliage and plant habit within the group. All cultivars were introduced without names, using a four digit numerical code (2-1-22 as an example) indicating time of bloom, type & size of bloom, and color of bloom. They are hardy to about 5°F (-15°C).

Kaempferi Azaleas

Kaempferi azaleas which originated in Holland are hardy to Zone 6, -5°F (-21°C). Graceful plants that become 5 to 6 ft. (1.5 to 1.8 m) tall after about five years, they bear many 2 in. (5.1 cm) flowers in spring. Toward the northern edges of their areas they lose some leaves in cold winters. Typical varieties are 'Barbara', deep pink; 'Fedora', deep pink; 'Holland', deep red; 'Mikado', bright red; 'Othello', orange red; 'Roehr's Peggy Ann', white with a purple-pink edge; 'Semperflorens', narrow red peals; 'Thais', crimson; 'Wilhelmina Vuyk', white; and 'Zampa', violet red. [Return to Hybrid Evergreen Azalea Index]

Klimavicz Azaleas

Joe Klimavicz has been hybridizing since 1989 in Zone 7. With azaleas from Bob Stewart and Pete Vines, Joe moved to his 1/3-acre lot in Vienna, VA. He makes about 10 crosses each year, and brings out of his basement close to 1000 new azaleas each year. The Klimavicz hybridization program is aimed at developing a plant that is vigorous, and disease and insect resistant, with a flower that is unusual and long lasting. They are hardy to 0°F (-18°C). He has registered 15 azaleas to date. His registered azaleas are described below.

More Klimavicz Azaleas

Kurume Azaleas

Kurume azaleas were bred at Kurume, an inland town in Kyushu, which is the southernmost of the four main islands of Japan. The ancestral forms, were brought early in the 19th century from sacred Mt Kirishima, and from them seedlings were raised and propagated by Motozo Sakamoto. On his death the collection passed to Kijiro Akashi, who developed the Kurume azaleas and is said to have raised most of those in cultivation. The azaleas of Mt Kirishima, are very variable in the size and persistence of their leaves, and also in their flowers, which vary a little in size, in degree of fragrance and greatly in color; the most common shades are rosy mauve to magenta, but salmon and salmon-red are plentiful; pink, scarlet and crimson are rather rare. Plants bearing white flowers are occasionally found'. The two species that grow on the mountain are R. kiusianum and R. kaempferi, and it is now thought that the polymorphism of the Kirishima azaleas is due to hybridization between them. Some of the Kurume azaleas show the influence of R. kaempferi quite strongly, but others, especially those with white or pale pink flowers, are very different from authentic R. kiusianum as grown in this country, yet show no influence of R. kaempferi. There appears to be some other element in their background, and it is suggested that this may be R. sataense.

In the 19th century Kurume was remote from the main horticultural centers, and its azaleas were scarcely known, even in other parts of Japan, but early in the 20th century a few reached Europe through the Yokohama Nursery Company, and others were imported by Dutch nurserymen. Among these were two of the most famous: 'Hinomayo' and 'Hinodegiri'. Apart from these, the Kurumes grown in Britain belong to the 'Wilson Fifty', so called because they were selected from Asahi's collection by the great plant-collector E. H. Wilson when he visited Kurume in 1918. Two sets of these fifty varieties (out of the 250 then grown) were bought by him for the Arnold Arboretum, where they were propagated and further distributed. Wilson gave English names to his Fifty, which are not translations from the Japanese but invented by him. They are rarely used, the Japanese names being more memorable, even if difficult to pronounce correctly.

They are not widely grown, partly because they are thought to be tender. A few are definitely tender, but these have mostly dropped out of commerce; the rest are hardier than generally supposed, though like many other evergreen azaleas they may suffer damage from frost when young. The flowers are small, but borne in wonderful profusion in late April or May. In several varieties the calyx is petaloid, i.e., converted into a sort of outer corolla, colored and marked like the true corolla. Although the result of several generations of breeding, they have retained the dense and comparatively dwarf habit of their wild ancestors. They tolerate full sun, and woodland conditions are quite alien to their nature.

They are hardy to Zone 7, +5°F (-15°C). After five to eight years in the garden, most Kurume azaleas become dense 18 to 30 in. (.15 to .3 m) bushes with small glossy leaves. In spring the foliage is hidden by 1 in. (2.5 cm) flowers. Typical varieties are 'Coral Bells', medium pink; 'Eureka', similar to 'Coral Bells' but hardier; 'Glory', salmon pink; 'Hershey's Red', rose red; 'Hino Crimson', crimson; 'Hinode Giri', bright red; 'Lorna', bright pink; 'Mother's Day', red; 'Polar Bear', white; 'Pride of Planting Fields', salmon; and 'Snow', white. For hardiness: 'Blaauw's Pink' salmon pink; and Karen', dark lavender, are hardy to Zone 6, -5°F (-21°C). [Return to Hybrid Evergreen Azalea Index]

Linwood Hardy Azaleas by Al Reid of Linwood, NJ

Linwood Hardy hybrids were developed by Al Reid by combining outstanding characteristics of greenhouse plants with the hardy azaleas. Flowers are double and semi-double, and most are hose-in-hose types. Plants are generally low growing. Many are hardy to at least 0°F (-18°C). Examples are ´Linwood Lavender´, vivid purple flowers, semi-double and hose-in-hose form; ´Janet Rhea´, strong fuchsia-colored flowers with white edges, semi-double, hose-in-hose form; ´Hardy Gardenia´, double white flowers with hose-in-hose form; and 'Garden State Glow', strong purplish hose-in-hose. [Return to Hybrid Evergreen Azalea Index]

North Tisbury Hybrids

The North Tisbury hybrids were developed, beginning in the 1960's, by Mrs. Julian (Polly) Hill on Martha's Vineyard, MA, from seed and cuttings sent by Dr. Tsuneshige Rokujo in Tokyo, Japan, from crosses he raised or seed he collected in Japan and Korea. Some are from R. nakaharai or crosses of this species. Most are low mounding, spreading ground cover plants. ´Joseph Hill´ is vivid red with a wavy margin that is a low creeping plant. ´Michael Hill´ is a strong pink with a red blotch that is dwarf spreading. ´Pink Pancake´ is a strong pink with red spotting that is low creeping. ´Wintergreen´ is a red with a red blotch that is dwarf spreading. They are hardy to -5°F (-21°C) except Pink Pancake is hardy to 0°F (-18°C). [Return to Hybrid Evergreen Azalea Index]

Pennington Azaleas by Ralph Pennington of Covington, GA

Pennington hybrids consist of 16 named cultivars developed by the late Ralph Pennington in Covington, Georgia. His former nursery had one of the largest collections of azaleas in the Southeast U.S. Most Pennington hybrids grow 3 to 6 ft. (.9 to 1.8 m) tall and are hardy to at least 5 degrees F (-18°C). Examples are ´Ralph Pennington´, single white flowers with a greenish blotch; ´Beth Bullard´, yellowish pink flowers, 3 to 4 in. (7.6 to 10.2 cm) across; 'Y. W. Pennington', double pink; ´Mike Bullard´, vivid red flowers; and ´Bill Bullard´, reddish-orange flowers. [Return to Hybrid Evergreen Azalea Index]

Pericat Azaleas by Alphonse Pericat of Collingdale, PA

Pericat hybrids were developed by Alphonse Pericat in Collingdale, Pennsylvania for greenhouse forcing but are as hardy as Kurume hybrids. Unfortunately, many cultivars in this group are not readily available in the nursery trade. ´Hampton Beauty,´ however, is obtainable. It has deep-pink flowers with a dark pink blotch. Pericat hybrids are generally of medium height [3 to 5 ft. (.9 to 1.5 m)], bloom mid-season, and are as cold hardy as Kurume hybrids [zone 7a, to 0°F (-18°C)]. Others include 'Autumn Sunset', single brick red; 'Helen', wavy pink; and 'Marjorie Ann', semidouble deep pink with red spots. [Return to Hybrid Evergreen Azalea Index]

ReBLOOM® Azaleas by Robert & Lisa Head, Seneca, SC

Bred in Seneca, South Carolina, by Bob Head, ReBLOOM™ Azaleas are similar his Bloom-A-Thon® azaleas and are said to bloom for 4-6 weeks in spring, and then another 12-16 weeks in summer and fall. ReBLOOM™ Azaleas are the product of a complex and long breeding program. He began with thousands of seedlings from many crosses between different azaleas, and gradually reduced them to the nine very best, which are the ReBLOOM™ Azalea series. The ReBLOOM™ are hardier than his Bloom-A-Thon® azaleas and hold their leaves better in winter. ReBLOOM™ azaleas are recommend for zones 6-9, being hardy to -10°F (-23°C). They should be planted in partial shade, rather than in full sun. ReBLOOM Azaleas vary in size between 1 and 3 feet tall, with a spread of 2 to 4 feet, depending on the varieties you choose. They are disease-resistant and first bloom in spring, then rebloom in the summer, and continue blooming until hit by a hard frost. There are 9 varieties in the series. They include 'Blush Elegance', pink, 1.5-2 ft. (.4-.6 m) tall; 'Cherry Pink Prestige', double pink, 1-1.5 ft. (.3-.5 m) tall; 'Coral Amazement', triple-petaled vivid coral, 2-2.5 ft. (.6-.8 m) tall; 'Firebrick Fame', red-orange double, 2-3 ft. (.6-.9 m) tall; 'Fuchsia Extravagance', violet-purple; 'Pink Adoration', warm pink, 1.5-2 ft. (.4-.6 m) tall; 'Purple Spectacular', purple; 'Red Magnificence', bright red, 2-3 ft. (.6-.9 m) tall; and 'White Nobility', pure white, 2.5-3 ft. (.7-.9 m) tall. [Return to Hybrid Evergreen Azalea Index]

Robin Hill Azaleas by Robert Gartrell of New Jersey

Robin Hill azaleas are from Robert Gartrell in New Jersey. The Robin Hill azaleas are bred for cold hardiness. Most are good to Zone 6, -10°F (-23°C). This group, consisting of 69 cultivars, is noted for having attractive foliage and large flowers that offer a spectrum of colors and color blends, many with soft pastel hues. Robin Hill azaleas bloom late and thrive in either sunny or semi-shady locations. Most plants are low growing [2 to 3 ft. (.6 to .9 m)]. Cultivars include ´Olga Niblett´, white flowers with yellow-green throat; ´Conversation Piece´, white to purple-pink flowers having wavy edges; and 'Hilda Niblett', pink with pale edges. For hardiness: 'Conversation Piece', pink and white mix; 'Gwenda', pale pink; ´Nancy of Robin Hill´, pastel-pink semi-double hose-in-hose flowers; 'Robin Hill Gillie', large salmon flowers with red throats; and 'Watchett', creamy pink, are hardy to Zone 5. [Return to Hybrid Evergreen Azalea Index]

Satsuki Azaleas

The Satsuki azaleas are late blooming azaleas from Japan with highly variable flower colors. In Japanese, Satsuki means fifth month of the Japanese lunar calendar (June). So plants bloom late (May, June and July), when most other azaleas are no longer blooming. Single, hose-in-hose and double flower forms are available. Flower size ranges from less than 1 in. (2.5 cm) to more than 5 in. (13 cm) across. Flower patterns include solids, stripes, multicolored sections, colored rings or margins, speckles and combinations of these. Many cultivars have variations of flower color and patterns on the same plant. They typically exhibit sporting a characteristic where the flowers are composed of two colors and no two flowers are exactly the same except those that are all one of the two colors. Most Satsukis have flowers that will be predominantly one color with blotches of the other color. Satsukis vary in hardiness but most are not very hardy. The hardiest are hardy to -10°F (-23°C) and some are only hardy to +30°F (-23°C). Since they bloom fairly late, it is best to plant in partial shade. The Gumpo azaleas are popular Satsuki azaleas in the US. Popular cultivars include ´Pink Gumpo´, single, light-pink ruffled flowers; ´White Gumpo´, single, white flowers with small flecks of purplish pink and a light-green blotch; 'Beni Kirishima', double, funnel-shaped, reddish-orange flowers; 'Miyo-no-tsuki', highly variable white with lavender-pink specks and stripes; and ´Wakaebisu´, deep yellow-pink flowers with rounded petals, hose-in-hose form. [Return to Hybrid Evergreen Azalea Index]

How to Grow Evergreen Azaleas

The most important factor in achieving vigorous growth is an acid soil mixture high in organic content. Many commercial growers set evergreen azaleas in pure peat moss, or in a 50-50 mixture of peat moss and coarse sand or perlite. A favorite mixture on the West Coast is 1/2 peat moss and 1/2 ground redwood, but in such mixtures, plants must be fed regularly.

Because the roots grow near the surface, a bed prepared especially for rhododendrons and azaleas need not be more than 12 in. (30 cm) deep; deep planting keeps the roots from getting the air they need. In fact, it is a good idea to set them about 1 in. (2.5 cm) higher than they grew at the nursery. Balled-and-burlapped plants may be transplanted in blossom but it is better to transplant them early in spring in areas where their hardiness is questionable, and in spring or fall where there is no likelihood of winter damage.

Cultivating the soil around evergreen azaleas would damage their roots. Instead, keep the roots cool and moist with a permanent 2 to 3 in. (5 to 8 cm) of wood chips, oak leaves, chunky peat moss or other light organic mulch. Plants that have been given a soil mixture rich in organic matter probably will not need feeding for several years. Do not stimulate fast growth because it produces long weak stems and few flowers. But if a plant seems weak or sickly, use cottonseed meal or a special rhododendron-azalea-camellia fertilizer, dusted on the soil early in the spring. For maximum flower production, pinch off faded flowers or the seed capsules that follow.

Hardy evergreen azaleas do not develop their full hardiness until after three seasons or longer. In general, they need protection their first three winters after they are rooted. Normally, they will be grown in a protected area the first winter. Then they will be container grown in protected areas the second year. Then the third winter they will be field grown in a somewhat protected area. Then the fourth winter they should have reached their full hardiness.

Evergreen azaleas can be sheared for hedge or border. Unlike rhododendrons, evergreen azaleas can be sheared each year after flowering to create a dense rounded plant. Highly trained Japanese gardeners prune evergreen azaleas extensively and with great results.

Rhododendron & Azalea News

Evergreen Azaleas
by Steve Henning
Valley Forge Chapter ARS

Examples of Evergreen Azalea Species

Examples of Hybrid Evergreen Azaleas

Examples of Evergreen Azalea Species