Posted by Brent Wilson on 8/5/2016 to Planting & Growing Tips
Evergreen azaleas are easy to grow in the ground or in containers provided they are planted right and in the right spot. With a little good advice you'll be growing them like the pros!
Here's a breakdown of what you need to know regarding planting evergreen azaleas in the ground or in containers and pots...
Evergreen azaleas grow in a range of soils provided the soil is well-drained, acidic, and somewhat rich in organic matter. As with so many other ornamental plants, constantly soggy or wet soils cause root rot and other plant diseases. When planting in heavy clay soil it's a good idea to add organic matter or soil amendment to loosen the clay and improve drainage. More on that in the Planting Instructions further down on this page.
How To Test Soil Drainage
If you are uncertain about soil drainage in the area you intend to plant your azaleas, it's well worth taking the time to test the drainage before planting. To test soil drainage, dig a hole 12" wide by 12" deep in the planting area. Fill the hole with water and let it drain. Then, after it drains, fill it with water again, but this time clock how long it takes to drain. In well-drained soil the water level will go down at a rate of about 1 inch an hour. A faster rate, such as in loose, sandy soil, may signal potentially dry site conditions and possibly a need to add organic matter to help retain moisture. A slower rate indicates poor draining soil and is a caution you need to improve drainage, plant in a raised mound or bed, or look for plants that are more tolerant of wet or boggy conditions.
Azaleas grow best in an acid to slightly acid soil ranging from 5.0 to 6.5 on the pH scale. Most average garden soils range between 6.0 to 7.0 on the pH scale.
Testing Soil pH
Soil pH is a measurement of the alkalinity or acidity of soil and is measured on a scale of 1-14, with 7 as the neutral mark. Any measurement below 7 indicates acid soil conditions, and anything above 7 indicates alkaline. If you're unsure about the pH of your soil and whether or not it's suitable for growing azaleas it's a good idea to test the soil pH in the planting area. You can quickly test soil pH with an inexpensive soil pH tester probe. To raise the pH (make more alkaline) you can add pelletized limestone to the soil. To lower the pH (make more acid) you can apply Soil Sulfur, Aluminum Sulfate, or Chelated Iron. Adding organic compost to the soil or using compost as mulch can also help to increase acidity and maintain acid soil conditions.
Learn More: What is Soil pH and How To Adjust It >
Evergreen azaleas will grow in full sun or part shade. At least 4-5 hours of direct sun per day or all day lightly filtered sun is recommended for best flowering throughout the spring, summer and fall seasons. In the Deep South, and other regions of the country that experience very hot summers with intense sunshine, Encore Azaleas might appreciate a break from direct sun during the hottest part of summer afternoons.
Planting Azaleas In The Ground
(Scroll down to see planting instructions for containers and pots)
If your soil drains well, start by digging your planting hole at least two to three times as wide and no deeper than the root ball of your new azalea plant. The wider the hole the better. Place native soil removed from planting hole around the perimeter of the hole, in a wheel barrow, or on a tarp.
Depending on the type, fertility and porosity of the soil in the planting area you might need to amend the native soil. When planting in dense clay or poor soil it is beneficial to thoroughly mix in some good organic matter, such as composted cow manure, mushroom compost, sand, and/or a good planting mix at a 50/50 ratio with the soil. When planting in very sandy, quick-draining soil you might want to consider mixing in some top soil, peat moss and/or compost to help retain moisture. When planting in fertile, loamy, well-drained but moist soil there is no need for adding a soil amendment.
To remove your azalea from the container it was growing in, firmly grasp the plant by its base and very gently lift and remove the root ball from the container. If the root ball is stuck in the pot either cut the container away or place the plant on it's side and tap on the side of the container to loosen the root ball. After having removed your azalea from the container, loosen some feeder roots around the surface of the root ball. Azaleas are notorious for becoming root bound in containers. If root bound, you can spray the sides and bottom of the root ball with a stream of water from a garden hose. This will help to wash away some soil from the exterior of the root ball making it easier to loosen roots.
If you are planting in well-drained soil set your azalea in the planting hole so that the top edge of the rootball is at or slightly above ground level (1-inch or so) to allow for settling. If your soil is moderately drained, which means it drains slowly after rainfall, the top of the root ball should be 2 to 3 inches above ground level. If necessary, add some backfill soil mixture to the bottom of the hole to achieve proper planting height.
Note: If the soil in the planting area is poorly drained (constantly soggy or wet) you can create a mound of soil completely above ground in which to plant you azalea in, or consider planting a different plant species tolerant of wet soils.
After setting your azalea in the planting hole, use one hand to hold the plant straight and your other hand to begin back-filling your soil mixture around the root ball, tamping as you go to remove air pockets. When you have filled the hole to the halfway point you can soak the soil. Then continue back-filling to the top edge of the root ball. If you are planting higher than ground level taper your soil mixture gradually from the top edge of the root ball to the ground level, as shown in the planting diagram above. To avoid suffocating your plant, do not put any soil on top of the root ball.
Step 6 (Optional)
When planting your azaleas in a location far from a water source, you can use remaining soil mixture to build a water retaining berm (catch basin / doughnut) around the outside perimeter of the planting hole, as shown in the planting diagram above. This basin will help to collect and retain water from rainfall reducing the need for hand-watering. The berm can be removed after a couple growing seasons.
Next, deeply water the planting area, including the root ball, to a depth equal to the height of the root ball. For an extra boost, to stimulate early root formation and stronger root development you can also water you newly planted azaleas with a solution of Root Stimulator, which reduces transplant shock and promotes greener, more vigorous plants.
Apply a 1 to 2" layer of cured shredded or chipped wood mulch or pine straw around the planting area to conserve moisture and to suppress weed growth. As the mulch decomposes it will add vital nutrients to the soil that your azaleas will appreciate. Do not use freshly chipped or shredded wood chips for mulch until it has cured in a pile for at least 6 months, a year is better. Avoid placing or piling mulch directly against the base of your plant as this could cause the bark to rot.
Watering Tips for Encore Azaleas
Because they do not like constantly soggy or wet soil, avoid overwatering or planting Encore Azaleas in a poorly drained soil that stays constantly soggy or wet. Well-drained soil is a must!
At Planting Time
Immediately after planting deep soak the soil in the planting area, including the rootball, to a depth equal to the height of the root ball. For an extra boost, to stimulate early root formation and stronger root development you can also water you newly planted azaleas with a solution of Root Stimulator, which reduces transplant shock and promotes greener, more vigorous plants. When planted during the winter dormant season plants will require less water. So, be extra careful not to overwater during winter!
During the First Growing Season
In average garden soil you should not have to water your newly planted azaleas every day. More often than not, this causes soggy soil conditions that can lead to root rot and other harmful plant diseases. In the absence of sufficient rainfall, water only as needed to keep the rootball and surrounding soil damp to moist. Keep in mind that deep soaking less frequently is much better than splashing just a little water on your azaleas every day. azaleas planted during the winter dormant season, when the plant is not growing and moisture is not evaporating from the soil as quickly, will require much less water.
When established, azaleas are quite drought tolerant. That said, if you see new leaves wilting or tips of stems bending over during a drought, this could be an indicator that your plants could use a good deep soaking. Always check soil moisture before watering.
Note: When watering with an automated irrigation system it's best to set your timer to water during the early morning hours and not in the late evening or at night, which can lead to the onset of fungus and other foliage diseases. During the first few weeks after planting, check soil moisture often and adjust irrigation time if necessary to keep the soil moist, not wet.
Planting Azaleas In Containers
Whether you're looking to spruce up a patio, porch or deck, or you live and garden in a USDA Zone too far north and too cold to grow them year round outdoors, azaleas are a great candidate for container gardens. In zones where they are winter hardy containers can be left outdoors year round. Where they are not cold hardy you can move containers indoors for the winter.
Azaleas growing in pots appreciate a moist but well-drained soil. Constantly soggy or wet soil can and often will cause root rot or other harmful plant diseases. When planting an azalea in a container or pot, we recommend using a quality potting soil or potting mix, or a 50/50 combination thereof. You can also add some pumice or perlite (maybe 10 to 20%) to the soil mixture to help with drainage.
Make sure to choose a container with a drainage hole(s) at the bottom, and one that is large enough to allow for 2 to 3 years of growth before shifting your azalea up to a larger size container. This might mean your planting pot would be 6 inches or more wider than the root ball of your plant.
Container color will matter as well. Not only will you want to pick a color of container that goes well with the flower and foliage color of your azalea, you'll also want to pick a container that matches the style of your home or other structures and other plants in the surrounding environment.
Many nursery & garden centers offer a wide variety of containers to choose from. Before heading out to buy a container take pictures of your home and the surrounding environment. Doing so will help you to choose just the right color and style.
Container Planting Instructions
Before filling your container with the soil mix, we recommend lining the bottom with shade cloth or a porous landscape fabric. This will keep the drain holes from becoming stopped up with soil.
Gently remove your plant from the nursery container it was growing in. Or, if you fear the plant may be damaged by pulling it out of the container, cut the container away. Then loosen some feeder roots from around the surface of the root ball.
Pour a small amount of your soil mixture in the bottom of the container. Set your azalea in the container and make necessary adjustments by adding or removing some soil so that the top edge of the root ball will sit 1/2 to 1" below the rim of the container.
Backfill with your potting soil around root ball, tamping as you go, until the level of potting soil is even with the top edge of root ball.
Water thoroughly until water starts to drain from the holes in the bottom of the container. Add more potting mix if settling occurs during watering.
Step 6 (Optional)
Apply a 1/2" layer of wood chips or sphagnum moss to soil surface to help conserve moisture.
Other Hepful Azalea Container Growing Tips
Before watering azaleas growing in containers make sure to use the finger test to check soil moisture. Only water if the top inch or two of soil has become somewhat dry to dry. Wilting leaves or stem tips bending over are a sign your plant might need water.
To add extra appeal and instant beauty to your container garden, plant annual flowers, creeping or cascading perennial plants, or low-growing ornamental groundcover or grass plants around the base of your azalea.
Feed azaleas growing in containers with a slow- or time-release plant food or water soluble fertilizer. Cease feeding two months prior to the average first-frost date in your area.
Related Articles from Our Experts
Questions? Contact Us!