Azaleas are a little bit picky flowers, but they are not too difficult to grow if you fulfill their primary needs.
These spectacular shrubs can reach 4 to 20 feet (1.2 – 6 m) depending on the type you choose. If you prefer growing them indoors, there are a few 2 feet (61 cm) tall dwarf varieties of azaleas as well.
|Evergreen or deciduous shrub|
You can expect your shrubs flourish in spring
Azaleas are shade plants, but a lot of varieties tolerate or even prefer full sun
|Most Azaleas are bud-hardy just in the Southern parts of the US. If you live in one of the Northern States, you should choose Azaleas that withstand the winter temperatures|
|Azaleas thrive best if the soil is acidic, well-aerated, and excellently drained|
|The soil pH||
4.5 to 6.0
|It is entirely intolerant to frost|
Astilbe, Viburnum, Mountain laurel, Fern, Pieris, Mahonia, and Gardenia
|Regularly water your shrub, and don’t allow that roots entirely dry out or become too soggy. Until the plant becomes well-rooted, water it two to three times a week. After three months, 1 inch (2.5 cm) of water weekly will be just fine|
|Applying 10-8-6 fertilizer specially designed for Azaleas will provide necessary nutrients for your plant|
The Most Popular Varieties of Azaleas
It is hard making a precise selection of Azaleas since there are thousands of varieties of those beautiful plants. I will recommend you my favorite ones.
Many gardeners prefer growing ground-cover Azaleas. One of the most popular evergreen varieties is definitely 1 foot (30.5 cm) high Joseph Hill, with its breath-taking bright-red flowers.
Most people grow tall, deciduous Sweet Azalea because of its snow-white flowers and elegant 20 feet (6 m) height.
These Azaleas are quite practical because they actually extend the blooming season.
- Flame Creeper – That is a ground-cover Azaleas with unusual orange blooms
- Weston’s Lemon Drop – It is impressive watching its peachy-colored buds while opening to vibrant yellow flowers in July
- Sweet September – It is one more exceptional late-bloomer with beautiful pink flowers
- The Royalty of the Garden – This variety is simply majestic shrub with all those pink or pinkish-white blooms
Differences between Azaleas and Rhododendron
Most people can’t make a difference between Azaleas and Rhododendron. The truth is that all Azaleas are included in the Rhododendron genus, but every Rhododendron is not Azalea. Let’s solve this mystery once and for all.
- Azaleas can be both deciduous and evergreen
- They bloom in early spring, and their funnel-shaped or trumpet-shaped flowers are all over the plant
- The color of flowers vary from white, yellow, orange, to purple
- The flowers have five male parts (stamens), five petals (lobes) and only one stamen per lobe
- Their foliage is small and has an elliptical shape and rough texture
- With a few exceptions, they are small-sized to medium-sized shrubs tall up to 8 feet (2.4 m)
- Rhododendrons are always evergreen
- They bloom in spring, and their bell-shaped flowers stick up over the foliage
- The color of flowers vary from white, lavender, to purple
- The flowers have ten male parts (stamens), five petals (lobes) and two stamens per lobe
- Their thick, leathery foliage can be small or big and has a paddle shape
- They can be shrubs or small, up to 25 feet (7.6 m) high trees
How to Plant Azaleas
The best periods for planting Azaleas are early autumn or late spring, and you can expect first flowers next spring. Keep in mind that some varieties bloom in June or July, so you don’t need to worry about why your new shrub doesn’t flourish in the expected time.
After testing your soil and determining the spot with enough sun and shadow, you can start preparing for digging. The hole, where you want to place the new plant, should be deep enough and at least twice as wide as the root ball.
After putting your seedling into the hole, fill it with the soil, water it a bit, and add some more of it on the top. I always place some organic mulch over the ground, around the new shrub. It is necessary to protect the shallow roots of your new plant from drying.
How to Grow and Care Azaleas
Try to plant young Azaleas approximately 2 to 6 feet (0.6 – 1.8 m) apart, to provide enough space for their healthy growth.
Azaleas are acid-lovers, which mean that they thrive best if you provide acidic soil with the pH range from 4.5 to 6.0 for them. Every increasing of the pH means that your Azaleas will suffer a nutrient deficiency, which results in the appearance of wilted, yellow foliage.
Luckily, many parts of the US have naturally acidic soil. If you don’t live in such a region, or the soil in your garden is alkaline, you can add sulfur or ammonium sulfate in the ground. It will help in making some corrections in the pH value. If you are not sure about these values, you can do a soil test.
Besides, your Azaleas will thrive just if their roots get enough oxygen and moderate moisture. Therefore, you should provide well-aerated and excellently drained ground for this gentle flower.
If the soil in your garden is poorly drained, solve the problem by planting your Azaleas in raised beds or containers. Also, a great solution is to add peat-moss in the soil before planting.
If your Azaleas look unhealthy with yellow, faded leaves, there are usually two possible reasons. They lack in iron because the ground is too alkaline, or their roots can’t get necessary oxygen because the soil is water-logged.
In average, Azaleas are shade plants. However, there are a lot of varieties which can tolerate full sun, especially if you grow this plant in colder, northern climates. Moreover, some of them even require direct sun.
That means that you should pick out the type which fit the light conditions in your garden. That is the only way to get attractive, lush foliage and plentiful, fragrant blooms.
Since flower buds of Azaleas always form before cold weather, you need to pick out the right shrub for your garden depending on the lowest temperatures during winter. It is essential for gorgeous flourishing you expect in spring.
If you live in one of the Northern States, you should choose Azaleas that withstand the winter temperatures in your region. For example, you need northern-bred types which can survive the temperatures lower than 45 F (7 C) since most Azaleas are bud-hardy just in the Southern parts of the US.
If you grow your shrub in a container, you can keep it indoors throughout the year. However, it would be better removing it in the garden in summer to let them enjoy full sun.
As I have already said, Azaleas have quite shallow roots which spread through the ground to a depth of just 4 to 6 inches (10 – 15 cm). Therefore, it is very easy for them to dry, which may lead to damage of the whole plant.
It is essential keeping the soil where you grow Azaleas evenly moist. Regularly water your shrub, and don’t allow that roots entirely dry out or become too soggy.
In general, when you grow your plant in a sunny place, you need to provide more water than when it is placed in a shaded spot in your garden. To prevent evaporation and retain the ground moisture, place a layer of mulch around your Azaleas.
While your Azaleas are young, they need to be watered two to three times a week. Approximately two months after planting when the shrub is well-rooted, you should start decreasing the amount of water and frequency of watering.
Do it gradually and after three months, one watering a week will be enough. In summer, regular, thorough, and deep watering should provide at least 1 inch (2.5 cm) of water for mature plant weekly. That way, the roots of your Azaleas will absorb enough liquid for lush and vigorous growth.
Take care to avoid overwatering because the soggy ground may cause disease of the root system. If it is possible, install drip irrigation in your garden, as an ideal solution.
Be prepared to purchase a premium 10-8-6 fertilizer, specially designed for Azaleas. It contains necessary nutrients for promoting healthy and lush leaves as well as beautiful flowers. Also, an excellent fertilizer should include ammonium sulfate, which will keep the pH of the ground in the desired ranking.
The proper fertilizer for your shrub will start feeding it immediately, with a prolonged effect of up to four months. Fertilizing the established plant in early spring and once more in late summer will provide all essential nutrients, including iron, calcium, magnesium, zinc, and manganese.
Spread the fertilizer about 6 inches (15 cm) around the plant, and water it abundantly. Strictly follow the instructions on the label to avoid over-fertilizing and damaging of the shallow roots.
Azaleas require a thick layer of mulch, which will conserve water, suppress the growth of weeds, and keep the temperature and the pH of the ground at the desired level.
Since the roots of Azaleas are shallow and can dry quickly, adding compost can help. Composted pine barks, pine needles, pine straw, hemlock sawdust, or oak leaf mold are perfect for this plant.
That way, you won’t need to cultivate this shrub, which will protect roots from damaging. Add a new amount of mulch annually.
Depending on the size of your shrub, the best options are to add:
- Approximately 2 inches (5 cm) of peat moss
- From 3 to 4 inches (7.6 – 10 cm) of pine needles
- More than 6 inches (15 cm) of oak leaves
You should prune your Azaleas regularly to keep its size and shape under control. There is no need to do that every year because many Azaleas do well with occasional and moderate cutting. However, when deciding that it is the right time for a new form of your plant, do it in spring.
Yet, don’t prune this plant on usual, formal way since they prefer growing naturally. Shape them to get straight edges and the shape of the box. You will be surprised during the next season when noticing much abundant flowering.
Remove old and damaged branches as well as these ones which stick out from the rest of the shrub with hand pruners. If it is the time to significantly reduce the plant’s size, do it, but always take care to leave its bottom a little bit wider than the top. That way, all the foliage will get enough necessary sunlight.
Pruning is also an excellent way to renew the growth of overgrown or elderly Azaleas. The best moment for this job is the beginning of spring. Be prepared that your shrub can’t flourish during at least a year. One more thing! Never cut branches more than one-third of their length.
Pests and Diseases
In most cases, Azaleas are not prone to diseases and pests. However, there are a few problems you need to solve to avoid damaging this magnificent, fragrant shrub.
This issue appears because of the high alkalinity of the ground and deficiency of potassium, calcium, and magnesium. The result is the appearance of yellow leaves. Feed your plant well, and it will become healthy and vigorous again.
Even though you water and feed your plants well, they can’t grow abundant if there are a lot of shrubs and trees around. Their roots use most of the nutrients and water from the ground, leaving your Azaleas without them.
Solve the problem by making a vertical, 20 inches (51 m) deep root barrier to keep the roots of nearby plants far away.
These small insects devastate the foliage of Azaleas which become discolored and spotted. On the underside of the leaves of your shrub, you can see tiny bugs, their excrement, as well as varnish-like spots.
To get rid of these insects, you should spray the undersides of the foliage with insecticidal soap or neem oil carefully and in detail. You will get the best result if spraying your plant in the period when adult insects lay eggs.
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My name is Peter Weeks, Writer of The Daily Gardener. Gardening has always been my passion, nothing gives me quite the satisfaction that feeling the soil sift through my fingers does. Give me a spade, a shovel, and a rake, and I can happily while away the day transforming a patch of land into a beautiful oasis. To me, gardening is life. It’s not a career. It’s not a job. It’s something that I truly love doing. It’s a way of life, a passion that I’ve no intention of ever giving up.