Azaleas are flowering deciduous or evergreen shrubs, with many hundreds of recognized species. Mistakenly referred to as rhododendrons, these plants actually belong to the genus of azaleas.
The azalea is a very popular ornamental shrub, due to its long-lasting floral display early in the year. While it’s true that all azaleas are under rhododendron species, not all rhododendron are part of azaleas!
History
Azalea shrubs are plants that come from China and Japan. During the early 1800s, they arrived in Europe.
They then quickly became extremely popular in America and are seen as symbolizing the start of spring in the Southern states. Nearly everyone has an azalea in their garden!
Plant Facts
| Scientific name | Azalea japonica |
| Common names | Japanese azalea |
| Genus | Rhododendron |
| Family | Ericaceae |
| Height | Up to 200cm (6.5 feet) |
| Width | 100 to 200 cm (3 to 6 feet) |
| USDA Plant Hardiness Zone | USDA zones 4 to 8 |
| Native to | China, Japan |
| Blooming season | Spring |
| Flower colors | Pink, red, mauve, white, yellow |
| Plant specific features | Massive and impressive display of blooms in Spring. Some varieties are fragrant and many species are evergreen. |
How to Plant and Grow an Azaleas Bush
Azalea is not a difficult plant to grow. It will reward you with a magnificent floral display, year after year, for little effort on your part. There are both evergreen and deciduous azaleas from which to choose and a great array of available colors too.
Where to Plant
The azalea is a shrub which in its evergreen form, heralds from Asia. They often grow in shady, woodland settings, in a cool position. Sunlight is necessary but should be dappled.
A slightly sloping spot in your garden, facing east or north will be ideal to provide protection from strong and drying winds. This is especially important in the winter and for evergreen azaleas.
If the soil freezes, then the water in the leaves freezes too, and damages the foliage.
When to Plant
Like most shrubs and perennials, the best time to plant azaleas is in the spring or fall. Spring is ideal because it is cool. The plants can become established during the growing season before the heat of the summer. Planting in the fall can be risky, particularly in a cold climate.
How to Plant
You should dig the planting hole twice the size of the container in which your azalea is planted. The base of the hole should be filled with compost suitable for ericaceous plants.
This will promote good drainage and ensure that the roots of the new azalea can spread into the soil easily.
The base of the azalea should sit just a little higher than the ground in which it is planted to ensure good drainage.
Azaleas Shurbs Care and Maintenance
Soil
Azaleas are shrubs which do well in well-drained, enriched soil that is slightly acidic. The ideal pH level is around 5. If your soil is not naturally rich in organic matter, then you should add a soil conditioner.
Alternatively, you can plant azaleas in raised beds or containers. You should mulch well. Azaleas are plants that have shallow roots; this can lead to them drying out quickly. A suitable mulch can discourage weeds and will also conserve moisture.
Water
It is important to ensure that the azalea does not dry out, particularly until it has become established. Because of its shallow root system, the shrub does tend to dry out quickly.
It is also unable to compete successfully with large shrubs or trees planted close for moisture and nutrients.
It is equally important to ensure that the azalea does not sit in stagnant water; this is a major cause of root rot which will kill your plant.
Fertilizer
If the mulch is applied at planting and replenished annually, then fertilizer is generally not required. The azalea will get all the required nutrients from the decaying organic matter.
If your soil lacks richness, you can apply an annual feed with a fertilizer designed for acid loving plants.
Sunlight
An azalea can not tolerate too much sun, particularly hot afternoon sun. Its leaves will burn, and the plant will die. This is especially true of the evergreen varieties of azalea.
However, the shrub still requires some sunlight; if it is deprived of sunlight, growth will be poor. The plant will become “leggy” and flower production poor.
If possible, plant in a spot that receives morning sun, but is sheltered from the heat of the afternoon sun.
Pruning and Repotting
Pruning azaleas can be beneficial. It can encourage new growth and keep the plant compact and bushy. If the shrub has been neglected, then good pruning will restore it.
You can prune back the branches of the azalea once flowering has finished.
Propagating
Propagation by seed is not possible as a reproduction method for azaleas. Germinated seeds will not produce a plant the same as the parent plant.
The best way to propagate azaleas which will be clones of the parent plant is by stem cuttings; take the cuttings once the leaves have appeared in late Spring.
Selected parent plants should be healthy and growing well. Cuttings should be around 5 inches (12.7 cm) long (13cm) and cut just below a leaf node.
When taking cuttings it is important that your tools, equipment, and pots are sterile. All flower buds and the lower leaves should be removed. The use of rooting hormone powder will speed up the rooting process.
Make a small hole in the compost and gently insert the stem cutting into the pot.
The pots should be placed in a well-lit position.
Only water when the growing medium is dry and cover it with the top of a plastic drink bottle. This will conserve moisture.
After approximately eight weeks, the cuttings should have developed small roots. At this stage, you can place the pots in a cool place to over winter.
By the following spring, they should have developed sufficiently to plant out in their final flowering positions.
Pests and diseases
Azaleas are not too often troubled by pests, but occasionally they may be infested by caterpillars which, if left, can quickly lead to leafless plants.
The most effective way to remove the caterpillar infestation is by hand-picking and removal.
Insecticides are also effective, and organic products are available. An insecticidal soap product will also control lace bugs, which are another pest common to azaleas.
Lace bugs will cause yellowing to the azalea leaves. Clusters of the bugs can be visible on the underside of the leaves.
In certain states, azalea bark scale can adversely affect azalea shrubs; this pest causes a sooty or cotton wool type of deposit at the joins of branches.
The best method to get rid of this problem is to apply horticultural oil at the base of the plant and where the branches fork. Affected branches should be removed and burnt.
Other Uses for
Azaleas are prized for their blooms in springtime. Often they are planted as a single specimen plant where their display will be fully admired.
However, mass plantings of azaleas can also be seen for example in the landscaping schemes of golf courses and the result is spectacular!
An azalea can also be an exceptionally successful container plant, although more care is required to ensure the plant does not dry out.
Types of You Can Grow
There is a vast range of sizes and colors available when it comes to azaleas. Some are slow growing and will mature to only a couple of feet in height (0.61 m), whilst others will soar to 20 feet (6m) or more.
Azaleas from Asia tend to be evergreen plants, and those from America are deciduous. The deciduous varieties are easier to grow successfully. They are hardier and flower well.
The azalea shrub has been cultivated for hundreds of years; plant breeders have developed thousands of hybrids from the hundreds of species that exist. Each year, more and more varieties appear offering more blooms, longer flowering periods, and new shades.
The variety of colors available offers the gardener a plant for any color scheme. Shades of red, orange, coral, pink, and purple are all available as well as white, lemon, and brilliant yellow too.
There is also a variegated azalea which will provide an additional season of interest. As well as the bright pink flowers in spring, the foliage of A. variegated gem is white-tipped and in the autumn will turn red.
There are also native varieties that grow freely in the wild. Beautiful and free flowering, these azalea shrubs can be seen framing river banks, at the foot of a mountain or in a woodland setting.
One such native azalea that deserves a mention is the sweet azalea (Rhododendron arborescens) which bears fragrant, white flowers in Spring and is hardy to USDA zone 4.
It will grow up to 20 feet (6.1 m) if left unchecked, and for this reason, is frequently referred to as the azalea tree.
Conclusion
For a spring flowering garden display, there is really nothing to beat the azalea. It’s no wonder that in many countries and cultures, there are even annual azalea festivals timed to coincide with the best flowering period.
The azalea is a flowering shrub like no other!
*image by NinaMalyna/depositphotos
