, Muskogee, OK

April 10, 2013

Soil for azaleas needs treatment

Plant does best in acidic, moist, well-drained area

By Molly Day
All the Dirt on Gardening

— Rhododendrons and azaleas belong to the plant genus Rhododendron, which is part of the heath family (Ericaceae). All members of this family including heaths, heathers, blueberries, mountain laurels and several others require acid soil, consistent moisture and good drainage.

Most rhododendrons and azaleas were originally from the Himalaya Mountains, in western China and northern India. Only a few are native to Japan, Europe and the U.S.

Every April, Ray Wright of Green Country Landscaping sells Muskogee-grown azaleas at Honor Heights Park.

 “My primary business is commercial and residential landscaping and irrigation, but we grow thousands of azaleas every year,” he said. “We grow shrubs and bedding plants for our jobs and then we sell some at Honor Heights Park and at the spring festivals.”

Green Country’s azaleas are all grown from cuttings at the company’s Muskogee greenhouses. Wright said he sells about 50 varieties, mostly hardy Karume, Girard and Poukhanense.

Karume hybrids, from Japanese stock, grow 4 to 6 feet tall and wide, with 1-inch leaves. Girard hybrids are an improved hardy variety. They have lustrous leaves, large flowers and hardiness to -15 degrees Fahrenheit (zone 5). The flower colors range from white to pink, red and deep orange.  

Poukhanense is a Korean azalea that slowly matures to 10 feet tall and wide, with magenta flowers.

Although Wright offers a variety of plant sizes, he recommended the 3-gallon size as ideal.

The new ReBLOOM azaleas from Greenleaf Nursery’s Garden Debut(r) collection are bred to be more compact than their standard re-blooming varieties such as Encore and Bloom-A-Thon. ReBLOOM colors include Red Magnificence, White Nobility and Coral Amazement this year. Additional colors will be marketed next year. The plants  are all cold hardy to -10 degrees Fahrenheit (zone 6).

Wright offers a brochure of several tips for success with azaleas at the business’ outlet in Honor Heights Park.

Among the tips:

• Select a planting area with afternoon shade but not too much shade, which will prevent blooming. Azaleas will succeed near lawn sprinklers where they can receive rain-like watering 20 minutes at a time. They thrive in moist, well-drained soil.

• To plant a $3 azalea, you’ll need a $5 hole, according to Wright. Local soil is usually sweet clay and has to be amended to be acidic (low pH of 5.0 to 5.5).

• Dig the hole 4 feet wide and 18 inches deep. Mix the soil you removed with baled peat moss. Plant the azaleas high so water will drain off or sink down.

• Top the planting area with an acidic mulch of pine bark, pecan shells, pine needles or cedar.

• Fertilize azaleas at half-strength in the spring and at full strength after the flowers fade. Never fertilize them in the fall.

• Prune the plants before July 1 by removing branches at the base, not by shearing them into hedges.

If you have an old plant in your landscape and would like to propagate a young one to continue the line, it’s fairly easy through layering. Remove all the leaves from a section of a low branch. Peg the branch section to the ground in a trench and cover it with good soil, leaving leaving one end attached to the mother plant and the other end sticking out of the soil with a few leaves still attached.  In a year, roots will emerge from the nodes where the leaves were removed. Cut the branch loose and plant it as recommended.

You can visit Wright at Honor Heights Park or contact him at (918) 261-0854.

The Rhododendron Society ( has a database of 400 azalea hybrids with photos, cold hardiness, mature height, leaf and flower color and size.