Azaleas are shrubs that can be evergreen or deciduous and belong to the same family as rhododendrons. Azaleas are one of the most popular of the spring flowering plants, able to be grown in most of the United States. Different colors can be planted together to make distinctive hedges or they can be used as stand alone specimen plants.
Deciduous azaleas can have flowers that are yellow, orange or red and leaves that turn orange, red and deep maroon in the fall. The evergreen's flowers will be pastel. Evergreen azaleas actually grow 2 sets of leaves each year. They loose one set in the fall and grown another one that falls off in the spring.
Azaleas like bright but filtered sunlight. Along the coast they need more direct sun. Azaleas can be grown as far north as zone 4 as long as they are given protection in the winter and are one of the very hardy varieties. They can be grown as far south as zone 9, which is the second hottest zone in the continental United States.
Azaleas can be planted in the fall or in the spring. The soil should be loose, well drained and contain organic matter. Dig a hole and fill it with water. If the water does not drain out in an hours time, you need to add a drain pipe to the bottom of the hole to aid in drainage, or simply mound up some soil to make a raised planting bed. Adding in some compost will make the soil organic. Azalea roots do not go deep, but they spread out, so prepare the soil to a depth of about 12 inches. Plant the azalia so it is higher than the soil line because it will settle. Water thoroughly and apply a thin layer of mulch.
Water the plant weekly during dry weather. Keep the soil moist, but not soaked. Azaleas should be pruned after the flowers are gone. Remove small branches where they are joined to larger branches. Do not prune after mid summer or you will be cutting off the buds for next years flowers. In late summer, you can check for any damaged branches. They should be removed at the point where the damage starts. An azalea that has a good mulch usually does not need fertilizer. If the leaves loose their deep green color, use a small amount of special azalea fertilizer. Too much fertilizer can burn the roots. Scorched leaf margins are a sign of too much.
Azalea Bark Scale is a problem in the east. The leaves are covered with sooty mold. Azalea Caterpillars can defoliate a bush. Azalea Lace Bugs turn the leaves yellow or white. Azalea Leafminers cause the leaved to develop brown blisters. Stunt Nematodes attack the feeder roots. Whiteflies kill the leaves.
Azalea Gall is a disease that attacks the leaves, turning them brown. Petal Blight is a fungus that attacks the flowers. Powdery Mildew attacks in the fall and causes the leaves to drop off early. Rust is a fungus that attacks the leaves and bark and can kill the plant. Twig Blight causes the branches to wilt.