Types Of Azalea – Growing Different Azalea Plant Cultivars

Types Of Azalea – Growing Different Azalea Plant Cultivars

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By: Teo Spengler

For shrubs with spectacular blossoms that tolerate shade, many gardeners rely on different varieties of azalea. You’ll find many that might work in your landscape. It’s important to select types of azalea adapted to the area in which they will be planted. If you’d like more information about attractive azalea plant cultivars, read on.

About Azalea Varieties

The explosion of blossoms on azaleas creates a show that few shrubs can rival. The generous load of blossoms in vivid shades makes azalea an extremely popular plant. Most azalea plant cultivars bloom in spring, but some bloom in summer and a few in fall, making it possible to have azaleas flower in your landscape for many months.

When we say there are quite a few kinds of azalea bushes, we aren’t exaggerating. You’ll find both evergreen and deciduous azalea varieties with different hardiness levels as well as varying blossom shapes.

Evergreen vs. Deciduous Varieties of Azalea

The two basic varieties of azaleas are evergreen and deciduous. Evergreen azaleas hold onto some of their leaves through winter, while deciduous azaleas drop leaves in autumn. The azaleas native to this continent are deciduous, but most evergreen azaleas originated in Asia.

The evergreen types of azalea are the more popular types for residential areas. On the other hand, deciduous azalea varieties work nicely in woodland settings.

Different azalea plant cultivars are also described by the shape or form of their flowers. Most deciduous azaleas have flowers in the shape of tubes with long stamens that are longer than the petals. Evergreen azaleas usually have single flowers, with multiple petals and stamens. The stamens of some semi-double flowers present like petals, while those azalea varieties with double flowers have all stamens transformed into petals.

Those kinds of azaleas with two flower shapes that look like one is inserted into another are called hose-in-hose types. They are known to hold onto their blossoms until they wither on the plant rather than falling to the ground.

Other Variations in Azalea Plant Cultivars

You can also group types of azaleas by when they bloom. Some bloom early, flowering from late winter into spring. Others flower in summer, and late-flowering varieties keep blooming through fall.

If you select carefully, you can plant kinds of azaleas that bloom in sequence. That might mean flowers from spring through fall.

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Florida Azaleas

Spectacular flower masses and colors, plant form, and evergreen foliage are among the reasons for the popularity of azaleas. Florida azaleas bloom from late February to early April, depending on cultivar and seasonal variation. Many azalea cultivars grow well in north and central Florida, but fewer are recommended for south Florida.

Azaleas can enhance the home landscape in many ways. They are used in foundation plantings, in mass borders, or as specimen plants. Generally, they are better adapted to informal landscape designs due to their open, sprawling growth habits. Large azaleas are useful as background for lower plantings, while low-growing ones are useful as foreground plantings. When choosing azaleas for your landscape, consider the following factors:

  • mature size and form,
  • flower size and color,
  • flowering season, and
  • adaptability.

Flower initiation follows spring growth, and flower bud development continues in late summer and fall. Flower bud dormancy is usually broken by exposure to temperatures below 50°F (10°C) for four to eight weeks followed by warm temperatures. Florida's warm winter temperatures may not provide adequate chilling for northern hybrids, resulting in sporadic flowering. Due to greater winter temperature fluctuation, sporadic flowering is more common in central and south Florida than in north Florida.

General Culture

Sun & Shade

Florida azaleas perform best in areas with filtered sunlight. Their shallow root system and low tolerance to poor soil drainage make placement and care important. Partial shade under pine trees or strategically spaced hardwoods provides conditions for healthy growth and optimum flowering. Dense shade reduces plant growth and flowering.

Azaleas exposed directly to early morning sun after a hard freeze are susceptible to cold injury. Rapid thawing of frozen twigs and branches may result in bark splitting. Death of branches with split bark may not occur until weeks or months after the injury.


Well-drained, organic soils with a pH of 4.5 to 5.5 are best suited for azaleas. Organic amendments and fertilization are usually needed to modify Florida soils for proper azalea growth. Fertilizers, organic amendments, and pH-adjusting amendments should be incorporated into the planting bed or soil backfill during planting.

Preparation of the entire planting area is best when a number of azaleas are being transplanted together. Organic amendments--such as peat, compost, or pine bark--help increase water and nutrient retention and lower the soil pH. A soil test will determine the pH of your existing soil and provide a basis for fertilizer recommendations.

Ample quantities of iron and other micronutrients may not be available in soils with a pH higher than 5.5. You can modify soils with a pH higher than 5.0 using applications of elemental sulfur. Excessive rates will injure plant roots, so apply no more than 1 pound of sulfur per 100 square feet of planting at one time, and apply sulfur no more than two or three times a year. Dolomitic lime should be incorporated to raise the pH of soils with a pH lower than 4.5. Soil adjustment should be made based on a recent soil test.


The planting hole for containerized or balled and burlapped azalea plants should be approximately six inches deeper and twelve inches wider than the root mass. An organic amendment--such as peat, composted leaves, or pine bark--can be incorporated into the backfill soil at a rate not to exceed one-third volume by volume. Generally, Florida azalea plants should be spaced three to five feet apart, but the ideal spacing varies according to the mature size of the cultivar.

Azaleas should be planted at or above the depth at which they grew in the container or nursery. An organic mulch applied to a depth of 2 - 3 inches will conserve water and reduce weed problems. November to February is the best season for transplanting, but containerized azaleas may be transplanted at any time if proper care is provided.


Irrigation is necessary for optimum plant growth during extended dry periods. Plants transplanted during the dry season into sandy soils may require watering of the root mass twice a week. Generally, established plants should be watered every 10 - 14 days during dry periods to wet the soil to a depth of 14 - 18 inches.


Frequent, light applications of fertilizers are necessary in Florida's sandy soils. Acid-forming fertilizers like 12-4-8 or 15-5-15 should be applied during each season--spring, summer, fall, and winter. Apply approximately ¼ pound to a mature plant or ¾ to 1½ pounds per 100 square feet.

Micronutrients should be applied routinely. Complete fertilizers containing micro-nutrients are available and can be used for normal fertilization. Soil and/or foliage application of only micronutrients have proven satisfactory, although soil treatments usually have a more long-term effect.


Pruning is necessary to obtain a full, well-branched azalea. Several light prunings early in the active growing season will result in compact growth and numerous branches on the present season's growth. Terminal vegetative growth stops after flower initiation and subsequent bud development. Pruning after flower bud initiation will decrease the number of spring flowers. Therefore, established plants should be pruned shortly after flowering.


Evergreen azaleas are usually propagated by cuttings to maintain hybrid characteristics. Azalea cuttings are rooted most successfully when they are taken after the spring growth has hardened or matured (June). Cuttings 3 - 4 inches long have proved satisfactory. Deciduous azaleas are usually propagated by seed or layering because cuttings are difficult to root.



The most common diseases reported on Florida azaleas include petal blight, leaf gall, and various declines.

Petal Blight

Petal blight is most severe during cool, moist weather. Infection first appears as small, white spots on colored petals or rust-colored spots on white flowered varieties. Spots enlarge rapidly into irregular blotches under moist conditions, causing the blossoms to "melt" into a slimy mass.

Affected blossoms dry and may remain or drop from the plants. The fungus survives in dried blossoms on or in the soil. Removing and burning surface mulch and dead flowers three to four weeks before bloom will reduce disease incidence. Directed ground sprays of a recommended fungicide one month before bloom will provide some control.

Leaf Gall

Leaf gall occurs during wet spring months and is most severe on densely shaded plantings with poor air circulation. Galls may occur on the leaves, stem, or flowers. Small numbers of galls can be handpicked and destroyed at first appearance. Large plantings should be protected by fungicide sprays starting at budbreak and continuing every ten days as needed.

Azalea Declines

Azaleas decline for various root-related reasons such as root rot diseases or nematode injury. Plants that exhibit stunting, chlorosis, and die-back symptoms should first be examined for problems with planting depth, soil pH or drainage. Plants in poorly drained sites often develop Pythium- or Phytophthora-caused root rot diseases. Feeder roots become mushy and discolored and the outer root layer (cortex) characteristically sloughs off when handled, leaving the string-like root center (stele).

Root Rot & Nematodes

Mushroom root rot often kills azaleas, especially those planted in sites with tree stumps or buried organic debris. The causal fungus will be visible as white mycelium under the outer bark layer of the crown or major roots.

Slow decline in plant vigor with general stunting may be due to nematode injury of the root system. Root examination will reveal galls or swellings, necrosis of fine roots, and/or general stubbiness of small roots, depending on the nematode involved.

Controls for both nematode and root rot diseases are primarily preventive. Dead or dying landscape plantings should be removed with as much of the root system as possible, and the soil should be sterilized before replanting.


Lacebugs, white flies, leafminers, spider mites, scale and stem borers are the most common insects that attack Florida azaleas.


Lacebugs are sucking insects found on the underside of the leaf. The top surface of the injured leaf appears speckled or mottled. Two applications of recommended insecticides at ten-day intervals sprayed on the lower surface of the leaf effectively control lacebug.

Leafminers & Leafrollers

Leafminers or leafrollers feed on azalea leaves during their larval stage. Two applications of a recommended insecticide at seven- to ten-day intervals will control leafminers. Leafrollers can be controlled by two applications of a labeled insecticide at fourteen-day intervals.

Spider Mites

Spider mite injury appears as a bronzing or rusty coloration of green leaves. A mite infection can be verified by placing a white piece of paper beneath the foliage and slapping the leaves with your hand. Mites can be detected on the white paper as moving, small red or brown specks. Two applications of a recommended miticide at five- to seven-day intervals will provide acceptable control.

Scale Insects

Several species of scale insects can be found on azaleas. Some have a white cottony appearance others are covered with a hard shell. Scales suck the sap from azaleas, resulting in yellow or unthrifty leaves. Two foliar applications of a recommended insecticide at two-week intervals applied during early stages of scale development provide adequate control.

Stem Borers

Stem borers in the larvae stage tunnel into stem and branch tips during late spring and early summer. The young stem will wilt and die back to where the tunnel ends. The best way to control stem borers is to remove infested branches and then apply a properly labled insecticide. Fungicide and insecticide recommendations are available through your county Extension office.

Condensed from:

"Azaleas for Florida" (ENH37) by Dewayne L. Ingram and James T. Midcap. Published by: Environmental Horticulture Department (rev. 10/2003).

Rhododendrons vs. Azaleas

How to tell the difference between azaleas and rhododendrons? Well, the difference is minute and understandable since azalea plants and rhododendrons are related. All azaleas belong to the Rhododendron genus, but not all Rhododendrons are azaleas. So if you read the botanical name of a common azalea on a plant label at the nursery, you will likely see the word, "Rhododendron."

The genus of Rhododendron is in the heath family, which also includes its namesakes, the heathers (Calluna vulgaris), Andromeda (Pieris japonica), and mountain laurels (Kalmia latifolia). Most members of the heath family require acidic soil. When you have naturally acidic soil in your yard, it is a lot easier simply to grow acid-loving plants rather than trying to change the pH level.

Keep in mind that there are also members of this genus that are just plain "rhododendrons." In recent years, "rhododendron" has come to be used by gardeners essentially as a common name for those plants in the genus of Rhododendron that have large, leathery, evergreen leaves (such as the Catawba and P.J.M. ). The leaves on azalea plants tend to be smaller by comparison. Within the rhododendrons, themselves, leaf-size comparisons are used to make a further division between large-leaf and small-leaf types.

On average, rhododendrons are larger shrubs than azalea plants, and they have larger leaves. Also, azalea flowers usually have five stamens, while the rhododendron flowers have ten. The stamens of a flower are those thin stems sticking out (they are male flower parts and produce pollen). Finally, unlike rhododendrons, many azalea plants are deciduous.

Evergreen vs. Deciduous Varieties of Azalea

The two basic varieties of azaleas are evergreen and deciduous. Evergreen azaleas hold onto some of their leaves through winter, while deciduous azaleas drop leaves in autumn. The azaleas native to this continent are deciduous, but most evergreen azaleas originated in Asia.

The evergreen types of azalea are the more popular types for residential areas. On the other hand, deciduous azalea varieties work nicely in woodland settings.

Different azalea plant cultivars are also described by the shape or form of their flowers. Most deciduous azaleas have flowers in the shape of tubes with long stamens that are longer than the petals. Evergreen azaleas usually have single flowers, with multiple petals and stamens. The stamens of some semi-double flowers present like petals, while those azalea varieties with double flowers have all stamens transformed into petals.

Those kinds of azaleas with two flower shapes that look like one is inserted into another are called hose-in-hose types. They are known to hold onto their blossoms until they wither on the plant rather than falling to the ground.

Azaleas Selection | See Our Azaleas


Azaleas are beautiful flowering shrubs that come from the Rhododendron Genus. Most Azaleas provide stunning blooms over the spring months that are sure to bring a surplus of color into any yard or landscape. They are best grown in areas with partial-sun and well-drained acidic soil. It is important to water azaleas regularly, especially when they are first established. Since their foliage also absorbs water, it is best to water both the leaves and the roots.
Here at Garden Gate we offer several different types of azaleas including Landscape Varieties, Florida Natives, and the Encore Series. Our branded Encore varieties have been engineered to blooms in Spring, Summer, and Fall! The Encore collection does require a little more sun than traditional azaleas, but make sure they still have some shade to keep from burning in the afternoon sun. There are also many azaleas that are native to Florida, such as the Florida Flame and Pinxter azalea. These indigenous azaleas are perfectly grown in Florida and can handle the sun and heat that is common to the Sunshine State. Azaleas can provide large areas of color and variety to a garden because of their captivating look.
We carry a large variety of Azaleas at Garden Gate Nursery that usually change depending on the season, but below are some we currently have in stock:

Fashion (Dwarf variety, Glendale Hybrid), 3G – Red (Salmon)
Vivid (Dwarf variety, Sanders Hybrid), 3G – Red
Red Ruffle (Dwarf variety), 1G/3G – Red
Happy Days (Dwarf variety), 3G – Purple
George Tabor (Southern Indica variety), 3G/7G – Pink (light)
G.G. Gerbing (Southern Indica variety), 7G – White
Southern Charm (Southern Indica variety), 3G/7G – Pink
Wakebishu (Rhododendron satsuki), 3G – Pink (light)
Harrell Supreme (Rhododendron sp.), 3G/7G – Red (light)
Lavender Formosa (Southern indica variety), 3G – Pink (lavender)
Red Formosa (Southern indica variety), 3G – Red

Autumn Sangria (Rhododendron ‘Robleg’) – 3G (white)
Autumn Royalty (Rhododendron ‘Conlec’)- 3G (Purple)
Autumn Embers (Dwarf variety, Rhododendron ‘Conleb’)- 3G (Red)
Autumn Angel (Dwarf variety, Rhododendron ‘Roblee’) – 3G (Pink)

Florida Flame (Native variety), 3G – Yellow.
Pink Pinxter/Piedmont (Native variety), 3G – Pink.

If you are interested in other Azaleas not listed above, see our complete Azalea Selection. You can make a request for specific azaleas by stoping by our store on 43rd Street or calling (352) 376-4922. If your request is available, we will ship your plant to our store and call you when it is ready for pick-up.

[divider]Come on by to Garden Gate Nursery and visit our Azalea selection. It is located in front of the store on the Eastern side of the nursery. While your here, visit our Native Azalea section as well, which is located in our Natives Section on the Western side of the nursery. Don’t forget to stop by the gift shop to pick up Azalea food!

[fancy_images width=”185″ height=”185″]
[image caption=”Encore Azalea, Autumn Rogue”]http://www.gardengatenursery.net/wp-content/uploads/azalea_autumn_rogue-1.jpg[/image]
[image caption=”Vivid Azalea”]http://www.gardengatenursery.net/wp-content/uploads/Azalea_vivid.jpg[/image]
[image caption=”Lavender Formosa Azalea”]http://www.gardengatenursery.net/wp-content/uploads/Azalea_Lavendar_Formosa.jpg[/image]

Written by RILEY SABBACK, Contributing Writer

QBARS - v17n4 Some Comments on Azaleas: Their Kinds and Origin

Some Comments on Azaleas: Their Kinds and Origin
Arthur E. Radcliffe, Pinehurst, N. C.

Azaleas can be divided for convenience into several classes, including Kurume, Pericat, Gable, Glendale, Southern Indica, Satsuki and Native. This last group is used here as including the deciduous Knaphill and Exbury varieties which include in their ancestry some of our American species.

The Kurumes are the early Japanese azaleas most frequently seen in eastern gardens. Even though their individual flowers are small they are borne in such profusion as to make the Kurumes a very showy group of azaleas. Little is known of their parentage as they have been grown in Japanese gardens for so long that it is impossible to trace them back to the wild forms from which they originated. The ones most commonly used are 'Hinodegiri', 'Hino-crimson', 'Christmas Cheer', 'Coral Bells' and 'Snow'.

The Pericat azaleas originated with a Frenchman living in Pennsylvania. He kept no records and kept his work a secret. His kinds most used are 'Madame Pericat', 'Pink Pericat', 'Hampton Beauty', 'Daphne', 'Salmon' and 'Dawn'. They are a class of early mid-season bloomers with an erect habit of growth and with flowers larger than the Kurumes.

The Gable azaleas originated with Joe Gable, Stewartstown, Pa. He has introduced a few very fine varieties his 'Rose Greeley' is one of the best whites. Its ruffled chartreuse tinted white flower makes a nice effect in a garden. His 'Rosebud' is the best of the double azaleas 'Purple Splendor' is the deepest purple 'Fuchsia' is an unusual shade of pink. 'Caroline Gable' and 'Louise Gable' have extra petals that give them a semi-double effect and their color blendings make them both outstanding. Then too Mr. Gable has introduced late bloomers as 'Jimmie Coover', 'Jessie Coover' and 'H12-G'.

B. Y. Morrison spent nearly a lifetime in his work with the Department of Agriculture in the perfecting of the large group of azaleas known as Glen Dales. In this work he used azaleas from everywhere, and kept most accurate records of his crosses which are most helpful to hybridizers that follow him. They include many whites, a world of pinks in every conceivable shade, and many shades of red found in no other evergreen azaleas. 'Vestal' is the popular white although 'Driven Snow' and 'Vespers' rate about as high. It is hard to name a pink for there are so many and tastes vary. 'Coquette' is rose-pink 'Fashion' is a deeper rose pink 'Greeting' is coral rose 'Illusion' is rose-pink and 'Rhapsody' is rose-red. 'Morning Star' stands out as a color all its own, an indescribable deep pink with a suffusion of yellow. 'Content' is a lovely shade of orchid-pink. It, growing with Rhododendron 'Roseum Elegans', both in bloom at the same time, creates an irresistible color blending in a garden. In reds 'Jubilant' stands out head and shoulders above all others as a deep rich velvety red.

Southern Indica Varieties

The so-called Southern Indicas constitute a group of azaleas originating from the crossing of two tall growing species from Japan. Very likely the name is from the fact that they came from the southernmost islands of Japan and were brought to Holland and Belgium by the ships of the East India Trading Company. They are associated with Middleton and Magnolia, for some of the first ones brought to America are still growing there. 'Pride of Mobile', 'Maxwell', 'Judge Solomon', and 'Pride of Summerville' are the varieties most common. They grow tall, to 6 or 7 ft., and bloom in late April or early May and range in color from pink to shades of pink mixed with lavender. Among these early importations from Japan a double form was found. Louis Van Houtte of Belgium is credited with finding these double forms among some Indian seedlings in 1858. No one knows how they came about and for want of a better name they were called, Rustica Flore Pleno, meaning in Latin, double flowers from the country. We still have a few remaining from the many propagated in Belgium between 1858 and 1875.

Some Double Varieties

The one lovely dwarf, 'Balsaminaeflora' with its tiny double pink flowers looking like miniature roses is an azalea standing alone because of its unknown parentage and because of its incomplete flower formation, having neither stamens or pistil. It is one for the plant collector and is a novelty in any garden. 'Benikirin', is a little taller growing, with flowers larger in size but having the form of miniature roses. It is salmon-red in color. These two are tiny treasures to delight the heart of a true flower lover. It is from the old Rustica Flora Pleno group, along with the infusion of other species, that Joe Gable evolved his lovely 'Louise Gable', 'Caroline Gable', 'Rosebud' and 'Jimmie Coover'. The double ones 'Andros' and 'Delos' introduced by B. Y. Morrison resemble them closely but Mr. Morrison says that they came from a cross between 'Vittata Fortunei' and 'Warai-gishi'. These azaleas from Southern Japan are a most interesting group perhaps back before the time when records were kept there may be a connection between the groups that accounts for their similarity.

Closely related to these are two azalea species that have played an important part in our modern hybrids. They are R. danielsiana (now considered synonymous with R. indicum -ED.) a species from China introduced into England by Captain Daniels of the old East India Company in 1830. It is a medium tall grower with flowers striped with rose and lavender pencil marks on a white ground. There are also lower growing forms with flowers in shades of pink or a pink and orange blending. They bloom relatively late. Selections from this azalea are called Macranthas. They provide a nice pink for use after most azaleas have finished blooming.

The species named R. simsii, a tender sort from Southern China, being native of a warm climate, flowers after only a short rest period and soon the Belgians found that hybrids of it could be forced into bloom very easily, so through this species came the gorgeous azaleas offered by the florist at Christmas time and at Easter.

Another group, the Satsukis, are the last to bloom of all the evergreen azaleas. This distinct group of very late bloomers are dwarf growing, to not more than 2 feet, with some varieties growing less than a foot high and spreading over the ground to form a mat of green. In late May or June they will cover themselves with ruffled flowers 2ВЅ inches or more across. 'Gyrokushin' covers itself with wavy white flowers making the plant look like a mound of fluffy white snow. 'How-Raku' grows a little taller but like 'Gyrokushin' appears as a mound of fluffy white snow in June.

'Wakaibisu', being introduced from a different source in Japan is classed as a dwarf Indicum but in every way it is like the other Satsukis. Plants of it were in full bloom on July 4th of last year. The large ruffled flowers of soft pink completely covered the mound of green leaves.

Many of the Satsukis have white flowers with rose or lavender pencil marks like the azalea, 'Vittatum Fortunei', introduced from Japan by Robert Fortune. This plant (probably a form of R. simsii) has been used at other times too. Mr. Morrison gives it as one of the parents of his popular variety 'Festive'.

One group in the Satsuki family is of special interest because the flowers are different than those of all other azaleas. They are large flowers, with reflexed petals of heavy substance, resembling the 'Rosy Morn' petunia flower. All these azaleas but one have names ending in -getsu, and even this one has a name that has reference to the moon. This ending, -getsu means "moon" as translated from the Japanese so there is 'Keisetsu', white throat with orange-red margin, 'Kingetsu', white throat with claret-red margin, 'Reigetsu', meaning 'Beautiful Moon' is white with red margin, 'Seigetsu' is 'Sacred Moon', a white flower with purple margin. Only one, the choicest of them all, does not end in getsu. It is 'Shinnyo-no-Tsuki', meaning the 'Moon of Eternal Truth'. It has a very large flower with a heavy petal that is wide and much reflexed. The flower is white with a reddish-purple margin making it a very striking thing, unequalled by any other azalea.

Beginnings of the Knaphill Hybrids

Every Carolinian should swell with pride because it was primarily from North Carolina that the native azaleas came to enable the hybridizers to develop varieties that take unharmed even the harshest changes the weatherman hands out. Circling the world to pick up species in China the hybridizers have blended four natives to produce a fine group of azaleas. The Nudiflora azalea, R. nudiflorum, contributed its beauty of form. R. arborescens provided its white purity of color and its unmatched fragrance. R. calendulaceum endowed it with colors found nowhere else in azaleas the world over. All these blended with the size of the Chinese Mollis azalea to form a class that has everything, hardiness, vigor, rapid growth, size of flower unequalled by even our choicest florists' azaleas and an elegance of fragrance that is not surpassed by even refined manufactured perfumes. Besides all this they have lush green leaves all summer, in contrast to many so-called evergreen azaleas. Then in late summer they take on glowing tints of striking reds before the leaves fall to show the beauty of chocolate-brown stems that stand out conspicuously in the drabness of a winter landscape.

The history of how these azaleas were evolved is most interesting. Andre Michaux, a French plant hunter, is credited with having named the flame azalea, R. calendulaceum, but to John Bartram is given the credit for having sent seed to England in 1734. There is a long period before there is any record of seeds from other native American species, until in 1820 P. Mortier, a Ghent, (Belgium) baker is known to have crossed R. calendulaceum and R. nudiflorum. A few years later he turned his hybrids over to Louis Verschaffelt, a nurseryman of Ghent. At about that same time J. R. Gowen, gardener for the Earl of Carnarvon in England began crossing these natives, but not until 1870 is there any record of crosses with the Chinese azalea, R. molle, until Anthony Waterer started breeding to develop what we now know as the Knaphill hybrids.

Not until 1922 did Baron Rothschild start his work with the best of the Knaphill varieties, to start the Exbury azaleas named for his estate at Southampton. It is said that he got his best results by "selfing" that is by selecting one plant and using the pollen from flowers on that plant to cross other flowers on the same plant. Raising as many as 10,000 seedlings in a year he would select possibly one plant when it bloomed and destroy all the others. In this way, over a period of years, seedlings would tend to produce colors very much like the plant from which the seed was taken.

Not until after World War II were his Exbury azaleas released to the public, and not until the last few years, when chemists developed the modern rooting hormones, have nurserymen been able to increase them by cuttings. Before that they could only be raised by layers which is a slow process. This is the reason they are just now appearing in nursery lists in very limited quantities.

In pink varieties there is 'Cecile' a lovely carmine-pink with a suffusion of yellow. 'Desert Pink', flesh pink 'Strawberry lee', its name describes it. In orange-red are 'Gibraltar', 'Renne', flame orange-red. In yellows are 'George Reynolds', 'Hotspur Yellow', in orange, 'Klondyke', in white, 'Ballerina', 'Exbury White', 'Altair', and 'Sonia'. 'Princess Royal' is the largest of them all and is the most distinct in shape.

This group, eventually, will supply outstanding varieties that will endure for years and grow into large plants that will produce literally thousands of flowers.

Watch the video: What Is the Growing Zone for Azaleas?