Around 1848, Belgian Indian Hybrid azaleas were planted at Magnolia Gardens near Charleston, S.C. by The Reverend John Drayton.  Their popularity spread rapidly and persists today.

Of course, the first azaleas in our country were the natives:  alabamense, atlanticum, canescens, viscosum, flammeum and others.  These are beautiful in their own right, and well worth collecting.  Remember to preserve our natural resources by purchasing propagated plants.  Do not collect plants from the wild. 

More recently, other asian species and hybrids have been introduced and gained wide acceptance.  Continued hybridizing has brought to an eager public a vast array of azaleas in every form, color and habit.

Azaleas are classified in botanical circles as Rhododendron.  They weren't always classified so.  Linneaus created a separate genus called Azalea around 1750.  But his separate genus idea has never been widely accepted.  Now azaleas are considered a subseries of rhododendron.

Azaleas may be deciduous (i.e. dropping their leaves during the winter) or evergreen.  Most of our native azaleas are deciduous.  The Belgian Indian hybrids (indicas) and most of the familiar asian azaleas are evergreen.

The primary considerations for growing azaleas successfully include planting site, soil characteristics, planting techniques, fertilizing and pruning.

The best site is one that is free from frost pockets, lightly shaded, and protected from high winds.  However, azaleas will thrive where the conditions are less than perfect.  For example, they will do quite well in full sun, provided they are not near a wall or pavement that reflects intense heat.

Soil should be acid, well-drained, and high in organic matter.  Azaleas prefer a pH between 4.5 and 6.0.  Amendments may be added if a soil sample so indicates.

Select plants that are adapted to your climate zone.  Important to remember:  Indicas don't do well above USDA climate zone 8a, canadense azaleas don't do well below zone 7a.  Some deciduous azaleas suffer under prolonged periods of intense heat.  A number of species and hybrid groups don't do well below zone 8a.

Azaleas are easy to transplant, and container grown plants can be planted at any time of year if proper care is given.  Choose high-quality plants.  Azaleas with weak growth and poor leaf color should be avoided.

Water your plant well before remiving it from the pot for planting.  After removing the plant from the container, the roots should be loosened or "teased" out.  Some folks slice the root ball in 2 or 3 places.  Other "butterfly" the roots by laying the plant on its side, cutting through the rootball from about halfway down the rootball to the bottom.  Then the two lower portions are spread outward.  This encourages good root penetration into the soil.  Use the method you feel most comfortable with.

Because they are shallow-rooted, azaleas must not be planted deeply.  To assure a proper depth, allow 1" of the root ball to remain above the soil surface after planting and backfilling.  If the top of the rootball sinks below the soil surface after watering, re-position it by raising the plant and firming soil under it.

Plants may be spaced in varying distances, depending on what you wish to achieve.  For a hedge, plant kurume, satsuki and their hybrids 2' to 3' apart; indicas and larger azaleas 4' to 6' apart.  For specimen plants, space kurumes and satsukis 4' to 6' apart.  Space indicas and larger azaleas 6' to 8' apart.

When backfilling, water well as you go; pressing out remaining air bubbles that may be entrapped.  Mulch should be applied to help maintain moisture levels.  The best mulches included shredded leaves, pine bark, and pine needles.  Straw, peanut hulls, and pecan shells may be used.  Never use green sawdust or peat which may compact and shed available moisture, directing it away from the root zone.  Mulch thickness should be between 2" and 3".

Besides retaining moisture, mulch protects the roots from winter damage, helps to maintain a high level of organic matter in the soil, encourages growth of beneficial organisms, and reduces weed growth.

Azaleas need plenty of water throughout their lifespan.  At least 1" per week is essential.  If natural rainfall doesn't provide this, irrigation is necessary.

A good fertilization program for azaleas is based upon these three factors:  (1) they thrive in acid soil; (2) they are easily injured by too much fertilizer; (3) they have low nutritional requirements.  It is best to determine the rate of fertilizaion based upon the results of soil tests in conjunction with fertilizer manufacturers' recommendations.

Nitrogen is necessary for plant growth.  Adequate available nitrogen will result in dark green foliage.  Shortages result in yellowish green leaves.  But because azaleas have low nutritional requirements it is easy to apply too much nitrogen, the result being serious injury or death to the plant.  Select fertilizers that contain ammoniacal forms of nitrogen, rather than nitrates.  Sodium nitrate and potassium nitrate tend to raise the pH to unacceptable levels and inhibit iron uptake.  The preferred forms include ammonium sulfate and urea-form nitrogen.

Phosphorus and potassium assist in development of flower buds, root growth, woody tissue and leaf tissue.  Phosphorus deficiency shows itself by a dull leaf appearance and reddening on the undersurface of the foliage.  Potassium deficiency is marked by yellowing between the leaf veins (chlorosis), scorching along the margins, and dead tissue spots on the leaves.  Excessive applications can damage azaleas.

Though considered a minor element, iron is essential for azalea health.  Iron deficiency also shows up as chlorosis, followed by complete yellowing of the leaves, scorched margins and defoliation.  Improper fertilizing, high pH levels, and toxic amounts of minor elements can inhibit iron uptake.  A quick remedy for iron deficiency involves applying a liquid iron spray.  In addition, a should sample should be taken and corrective measures begun as recommended by your nurseryman or cooperative extension agent.

Calcium is also important for azaleas.  A deficiency is marked by chlorosis, tip burn and twisted leaves.  Gypsum or calcium sulphate can be added to the soil according to experts' recommendations to correct the problem.

Azaleas require little pruning, but what is done must be done correctly.  Principally, pruning involves removal of dead wood, and some shaping.  Most pruning should be done right after flowering is completed.  Smaller growing azaleas, like satsukis and kurumes, can be pinched until midsummer to encourage compact growth.  Large azaleas can be trimmed of long branches, rejuvenated by cutting them back to near-ground level, or opened up to expose the multiple "trunks" and allowed to grow as small trees.

Azaleas pruned after midsummer will have fewer blooms the following season.  In addition to their standard use in hedges, foundation plantings, or specimen plantings, certain varieties of azaleas can be chosen for use as potted plants, in hanging baskets, standard tree forms, espaliers and bonsai.