Over 10,000 different azalea varieties exist; there is one that will suit your climate and taste. Called "the royalty of the garden," azaleas sport a wide range of flower colours, shape and growth habits in an easy-to-grow perennial shrub. Sharing a genus with rhododendrons, these plants share many characteristics. However, azaleas normally have five or six stamens, while most rhododendrons have 10. Many azalea flowers are two to three inches long and can be single, double or hose-in-hose, with up to 30 petals per flower.
Azaleas are in the heath family and have existed as native plants in Japan for 70 million years. In 1680, azaleas were introduced into northern Europe. Azaleas were first called Azalea indica because they were thought to come from India. The first English azaleas were developed in 1830. Much cross breeding has been done in Europe, where it was considered an aristocratic plant. Major collections exist in England, France, Germany and Russia, but azaleas are enjoyed around the world.
Blooming Season and Needs
Depending on the variety you choose and your climate zone, you can expect azaleas to bloom as early as March and as late as August or September. Most varieties thrive in climates with winter low temperatures that range from -10 to +-6.67 degrees Celsius. They prefer to grow in shady conditions in soil that is acidic, with a pH from 5.5-6. They like an acidic mulch of materials such as pine needles. Good drainage is a must for azaleas.
When to Plant Outdoors
Sometimes you might not know the exact variety of a gift azalea. When you want to plant an azalea of unknown variety outdoors, wait until after your final frost because it might not be frost hardy. Also, new growth begins in the spring; this is the best time to transplant azaleas. If you want to try starting azaleas from seed, it's not hard to do. Start seed in the winter. When seedlings are several inches tall, transplant them to the garden in the spring.
How to Plant
Plant your azalea in spring in a shady area with soil that is loose, moist and well drained. Azaleas like a mix of half organic matter---pine bark or rotted leaves are recommended. Dig a hole slightly larger than the root system and then set the plant in, filling the hole to the top of the roots. Apply two to four inches of mulch but do not allow it to touch the stem. Water it deeply and water again the following day. Continue deep watering once each week.
Upkeep and Maintenance
Azaleas enjoy a fairly pest free life and don't need much fertiliser if you keep them well mulched. Inorganic fertilisers are not recommended because they make the plant dependent on them. If you feel the need to fertilise your azalea, test your soil. If it is acidic, skip the fertiliser. If you do need to fertilise, do so in winter. Prune azaleas in early spring before new growth appears. Prune in gradual stages to prevent the plant from going into shock.