The sight of an azalea growing strong and blooming in full splendor is certainly one of the tell-tale signs spring has arrived.
Azaleas are a flowering shrub that burst with color as spring hits full stride. In fact, their blooms can be so dense, it’s often hard to see the shiny foliage that lies beneath their flowering canopy.
With bloom periods lasting as long as two to three weeks, they can quickly bring the landscape into full color. And are those colors ever something to behold! Azalea varieties can be found flowering in a near endless array of bright hues, all of which seem to dance off the shrub.
But establishing azaleas and getting them to thrive can be a bit tricky for some gardeners. Most often, it’s due to selecting the wrong variety for your climate and location, or an issue with soil and light.
Here is a look at how and where to grow azaleas for success, along with some key maintenance tips to keep your azalea bushes blooming strong for years to come.
Azaleas are a member of the Rhododendron family, and share many of the same qualities and similarities as their cousin. In fact, many varieties of azaleas are so similar in size, shape and bloom, they are often mistakenly confused for a Rhododendron.
From dwarf varieties that mature at just a few feet in height, to others that soar to 10, 15 and 20′ or more, there is a size to fit every space. Like rhododendrons, azaleas can be found in both evergreen and deciduous varieties that lose their foliage each winter.
When, Where & How To Plant Azaleas
The first secret to successfully growing azaleas is to select a variety that is best-suited to your local climate. Known by many as a southern blooming shrub, there are actually many varieties that are hardy to temperatures as low as 20 to 30 below.
Typically, cold hardy varieties will struggle to survive in the warmer climates of the south. Conversely, azaleas that thrive in the south typically cannot survive the northern winters.
No matter where you live, planting azaleas in the early spring is best. It allows the plants time to establish in the soil before the heat of summer sets in. Fall planting can occur in southern climates, but a cool winter can certainly adversely affect late season plantings. For that reason, planting azaleas in the north in mid to late fall is never a good idea.
Where to plant your azaleas also depends once again on your location. Although azaleas are generally regarded as a shrub that enjoys more shade than sun, to thrive and bloom in the northern states, they need to be located in a sunnier location.
This helps to warm the plant early and produce more prolific bloom cycles. In northern climates, a good rule of thumb is to plant azaleas in locations that receive at least 4 to 6 hours of full sunlight.
When planting in warm southern climates, place in a location that receives more shade than sun. Unfortunately, the hot summer sun can take a toll on the foliage of plants with too much exposure. No more than 4 hours of direct sunlight is best for southern locations.
Soil Requirements For Growing Azaleas
As a fellow member of the Rhododendron family, azaleas prefers a more acidic soil for strong growth. PH levels should range somewhere between 4.0 and 5.0 for optimum growth. A soil that is too alkaline can result in poor plant growth, with little to no blooms in the spring.
If your soil leans to the alkaline side, you can amend it with ammonium sulfate to help lower the PH. In addition, mulching with pine bark or needles can help to lower the PH over time as well.
When planting, dig the planting hole to twice the circumference of the potted plant. Amend the planting hole with 25% compost to help supply vital nutrients and loosen the soil. Azaleas can suffer if they sit in too much moisture, and the compost will help promote better drainage.
Plant with the top surface level of the potted plants slightly above the soil line. This again will help excess water drain away from the crown and prevent rot. Mulch with a 3 to 5″ layer of pine nuggets, pine needles, shredded oak leaves or straw to help the plants retain moisture. Avoid using hardwood bark mulches as they can raise the PH level over time as they break down.
Watering & Fertilizing – Growing Azaleas
Azaleas need a fair amount of water to flourish, especially when they are first transplanted into the ground. If plants are not receiving at least 1″ of rainfall per week, supplement with hand watering. Water at the base of plants to avoid soaking the leaves.
Azaleas are prone to mold and fungus, and excess water laying on the foliage can encourage both. To further avoid these issues, always water in the early morning so the leaves can dry quickly with the warmth of the day. It’s just one more reason that northern planted azaleas need a bit more sun to reduce the chance of mold.
Azaleas can benefit from a yearly dose of fertilizer to help promote fuller bloom cycles. But when and what you fertilize with is extremely important. Many common plant fertilizers are not formulated to handle the nutrient and PH needs of azaleas.
Use a fertilizer that is specifically created for the Rhododendron family of acid loving plants. A fertilizer in the 9-15-13 nutrient range is most ideal. Product Link : Azalea Fertilizer.
Azaleas do not require pruning to continue blooming from year to year. Shaping and cutting back can occur if the plant is a bit out of control, but the timing of the pruning is extremely important. Azaleas, like rhododendrons, form their flowering buds in the summer for the following year.
If a plant is pruned in the summer or fall, the buds are lost and the plant will not flower the following spring. If pruning is needed, cut the plant back as soon as it finishes blooming. This allows time for summer growth and for buds to form for the following spring.
Here is to planting and growing azaleas successfully in your landscape!
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