Few plants rival the spectacular beauty of azaleas in full bloom. Available in shades of pink, purple, red, and white, the number of blossoms for each azalea type varies, as does the shape of its petals. Some can reach significant sizes, but some are dwarf in size, such as miniature varieties of Azalea japonica.
Azaleas can get as big as 10 feet (1 meter) depending on their type. However, there are thousands of varieties of azaleas, according to experts, and their size can vary significantly. Smaller ones are as low as about 12 inches (30 cm). And, the width of an azalea typically corresponds to its height.
The rest of this article will discuss the sizes and types of azaleas, how to grow azaleas, and issues surrounding their toxicity.
Sizes and Types of Azaleas
Azaleas vary significantly in size with dwarf varieties growing to heights of about 1 foot (0.3 meters) to 2 feet (0.6 meters). On the other end of the spectrum, large types can grow to as much as 12 feet (3.7 meters) and higher, and there are several varieties in between.
Most evergreen varieties originated in Japan, while native North American species are all deciduous.
Hybrid azaleas have been around for centuries, and the Azalea Society of America reported that almost 10,000 varieties are currently cataloged.
Popular varieties of azaleas include:
- Gable hybrids: Gables are resistant to cold temperatures, but don’t grow well in coastal areas. Their growing season runs from April to May. Colors include white, pink, and purple. Gable Hybrids range in height from about 2 feet (0.6 meters) to 4 feet (1.2 meters).
- Glen Dale hybrids: Glen Dales grow about four to six feet tall and three to four feet wide. Their blooming season varies by specific type flowering as early as March and as late as June. Colors include peach, deep rose, rose with a dark blotch, and white with pale green. Glen Dale hybrids range in height from about 4 feet (1.2 meters) to 6 feet (1.8 meters).
- Kaempferi azaleas: Kaempferis are tall and highly resistant to cold temperatures. Their blooming season begins in late April and runs through early May. Colors include white and pink. Kaempferi azaleas range in height from 4 feet (1.2 meters) to 10 feet (3 meters).
- Kurume azaleas: Kurumes are compact plants that can withstand cold environments. Their blooming season begins in late March and extends into the middle of April. Colors include white, pink, and red. Kurume azaleas range in height from 1 foot (0.3 meters) to 6 feet (1.8 meters)
- Satsuki azaleas: Satsukis are low-growing hardy plants suitable for all climates. Their blooming season runs from May to June. Colors include white, pink, and white with a rose-colored border. Satsuki azaleas range in height from 1 foot (0.3 meters) to 3 feet (0.9 meters)
- Indica azaleas: Also known as Indian azaleas, Indicas have large leaves and flowers. Their blooming season runs from late March to early April. Colors include pure white pink. Indica azaleas range in height from 6 feet (1.8 meters) to 10 feet (3 meters).
Growing and caring for azaleas is easy. However, to keep your azaleas healthy, you need to select a proper location for planting. Next, you will need to prepare the soil and follow appropriate planting procedures. Additionally, azaleas require the appropriate use of mulch and fertilizer. And eventually, they might require pruning.
Azaleas prefer cool locations with partial shade. Additionally, they typically require moist woodland soil. However, there are exceptions as some varieties flourish in excessively damp areas while others do better in dry soil.
Azaleas love morning sun and afternoon shade. So, keep that in mind when selecting a location for planting. Generally speaking, azaleas that bloom during the summer months require more shade than plants that bloom in the springtime.
Additionally, always plant azaleas in a location offering protection from the wind. Fences and other barriers provide excellent protection as do taller evergreen trees and shrubs. Likewise, do not plant them next to shallow-rooted trees like ash, elm, or maple.
Important: Always avoid planting azaleas next to driveways, unshaded sidewalks, or walls facing westward as they radiate heat that can cause moisture stress during the summer.
It is best to plant azaleas during the autumn months. However, you can plant them year-round. Garden centers typically stock up on azaleas during spring, but you can find a variety of colors online at any time of the year.
For example, you can purchase Autumn Twist, multicolor re-blooming evergreen shrubs online. This variety of azalea features a combination of solid purple blossoms mixed with white blooms with purple stripes.
Azaleas require well-drained soil with an acidic pH between 4.5 and 6.0. Soil pH test strip kits are available online for a nominal fee, or you can take a soil sample to your local community extension service.
You should loosen the soil when planting azaleas rather than digging individual holes for each plant. For best results, plant your azaleas at the same level in the ground as they were in the container.
Then, make sure you mulch your azaleas with about a three-inch layer of pine bark or cedar chips to help keep the soil cool and to preserve moisture.
Last but not least, to help settle the soil water, your azaleas thoroughly after you finish planting them. Water your plants weekly if you do not have enough rainfall, and be sure to fertilize them in the springtime and early summer with proper-balanced plant food for azaleas like this Miracle-Gro formula.
You can shorten them if necessary.
There are a variety of different techniques used for pruning azaleas. The heading is one technique and involves cutting back branches to form and shape the plant. Likewise, thinning involves the removal of a branch completely back to another branch, bud, or the main trunk.
Thinning helps open up the plant’s canopy, which improves airflow and minimizes the chance of the plant getting a disease. In the extreme, azaleas can be cut back to within about a foot of ground level to prompt the growth of an abundance of new shoots from the remaining base.
Under suitable conditions, they grow faster.
The speed at which azaleas grow varies depending on a variety of factors to include growing conditions, weather, and how old they are when purchased.
Additionally, the growth rate of azaleas varies depending on the variety. For example, southern Indian hybrids experience rapid growth as do kurume hybrids. Other types enjoy more moderate growth rates, and some hybrids like George Franc grow extremely slowly.
Nutrient-poor soil can slow or stunt growth, and although azaleas don’t require much fertilization, periodic use does increase their growth rate.
Azaleas are typically available in one-gallon, to seven-gallon nursery containers. The plants in one-gallon containers are about two to three years old and take about six to seven years to reach full maturity. The shrubs in the seven-gallon containers typically take around three to four years to reach maturity.
Interestingly, the rate of annual foliage growth and resulting height slows as azaleas age. For example, one-gallon plants range in size from 9 to 12 inches. However, azaleas purchased in seven-gallon containers are typically between 24 and 30 inches tall.
Growing azaleas doesn’t take a lot of time or money, and the rewards are bountiful. With proper care, azaleas are a welcome addition to any garden.
If you plan on growing azaleas, you might consider bookmarking this article for future reference.