Flowering azaleas are available for use indoors as potted plants throughout the year. However, it is during the late winter and early spring that they are often more common, more economical, and provide a colorful prelude to spring. The range of colors from red through many shades of rose, pink and salmon along with white fit well into many color schemes.
Although the petals of azaleas may seem fragile, the plant will provide several weeks of display if given proper care. Purchased plants often have open flowers along with some unopened buds that should develop to extend the display even longer.
Good light, careful watering, and cool temperatures are essential. Watering is particularly critical. Never let the soil dry out, but do not drown the plants. Today most potted azaleas are grown in a mix which is primarily organic matter such as peat moss which may not contain any soil. Even if soil is included, it is usually in very small amounts. Azalea roots are thin and delicate. Many are primarily along the outer areas of the pot which is first to dry. Excess drying of this highly organic medium causes roots to be killed quickly. How frequently watering is needed depends on pot size, indoor temperature, humidity and light. However, in an average home a thorough watering every two to three days should be adequate.
One of the best ways to water a plant in a highly organic mix, especially after it may have become fairly dry, is to submerge the pot in a bucket of deep water. If very dry it may tend to float, but allow it to remain until is settles somewhat, or anchor it down with a weight. Allow the pot to remain submerged until bubbles stop rising. Plant branches and flowers should remain above the water. After 5 to 10 minutes, remove the pot, let the excess moisture drain and then return the plant to its saucer and original location.
One of the easiest ways to determine a need for water is to notice the weight of the pot as you lift it. Remember to notice after you have watered a plant how heavy it feels. In a day or two lift it slightly and notice how much lighter it feels. As the pot begins to feel fairly light, but the surface may still be lightly moist it is probably time to rewater. If plants become too dry, flowers wilt first, and their life is shortened. If drying is not too far advanced they will recover.
In order to determine what to do with an azalea after flowering is finished, some knowledge of the type of azalea it is may be helpful. Most azaleas used as flowering potted plants are not reliably hardy in our climate. It is possible to rebloom potted plants for future years. However, conditions to accomplish this must be fairly exacting. After flowering is complete, the plant should be placed in a cool room at a sunny window. If a greenhouse is available, the process becomes easier.
Azaleas that have finished flowering and are to be kept for reblooming do not always need repotting, however, if they are in very small pots, repotting may be advisable. A good mix of three parts acid peatmoss and one part soil might be used. Commercial potting mixes are also quite satisfactory. Do not disturb the existing root ball, but pack the fresh mix around it to fill the larger pot.
In April after danger of any cold weather other than a very light frost is past, they may be moved outdoors. Place them in a lightly shaded spot where they may remain for the summer. Always keep the plant moist. During the heat of summer, daily watering is often necessary.
As plants grow. little needs to be done except for watering and a monthly fertilization with an acid reaction fertilizer. To keep plants compact and attractive, clip back long shoots as they form. Plants should be allowed to remain outdoors as long as possible in the fall. While they can tolerate a light frost, they should not be exposed to much cold or flower buds that form in the fall may be killed. For the buds to develop flowers next winter, plants that are brought back indoors must be kept in a cool room where temperatures are 40 degrees or slightly below for about 3 months (usually October through December).
If plants purchased in pots are known to be reliably hardy types, the process is much easier. These may be planted outdoors in April or May into beds high in organic matter in a shaded location. A mulch and summer watering is important since azaleas have a very fine and fairly shallow root system. Acid soil and excellent drainage are also necessary.
Healthy azaleas can be grown in a raised bed underneath a canopy of pine trees, as they need moisture but will rot out if the ground is too wet. Learn the tricks to growing azaleas with helpful tips from a sustainable gardener in this video on growing flowers.