It may take another growing season to see the life come back to your burned azalea plant.
Azaleas that have brown leaves, usually starting along the edges of the leaf and continuing to brown towards the middle, may have burned leaves. This can be caused by too little water, frost, too much fertilizer, transplant shock, and even too much salt in the dirt. In burns caused by salt, the lower leaves of the plant will be damaged and may fall off the bush. Bushes affected by frost may also have stems that are split. The condition is not caused by parasites or disease, but it does leave your plant susceptible to diseases and parCredit: Flickr: cbellh47asites. To revive a burned azalea bush you will need to correct the conditions that caused the leaf burn and provide the right growing conditions for your bush.
Too Much Fertilizer or Salt in the Soil? Flush Out the Fertilizer and/or Salt
Flush the pot or ground where the azalea is planted with water for plants affected by too little water or too much salt and/or fertilizer. If the plant is in a pot, fill it to the brim with water and let it drain. If the plant is planted in the ground, place a hose near the bush and let it run for about 10 minutes.
Flush the plant again in 24 hours. Too much water and water soaked roots can also cause problems for your azalea. Therefore you want to give it time to drain before flushing the soil again.
Prune the Plant
Cut off the burned areas of your azalea plant with pruning shears. You only need to cut off the affected leaves, but can prune the entire bush to give it a more uniform shape.
Trim off any stems that are split due to the cold. The open stems leave the plant more susceptible to disease and should be removed.
Prevent Further Damage to Your Burned Azalea Plant
Add about 2 to 3 inches of mulch to the base of the plant. This will protect the roots from burning and help plants in dry areas stay hydrated.
Move plants out of the sun. Azaleas need to be in mostly shade. Keeping the plant in the sun will only burn it again.
Protect the azalea from frost by bringing them inside, onto a covered porch or covering them with a tarp at night. This will prevent burns and bark splitting caused by the cold.
You do not need to fertilize azaleas regularly. According to Clemson University,”Azaleas have low nutritional requirements compared to other shrubs” and they “...do not have to be routinely fertilized during the growing season.” Only fertilize if your plant is showing signs of needing fertilizer, such as slow growth or changes to the leaf color. You may want to have your soil tested by a local nursery to determine if you really need to add fertilizer to your azalea plant’s soil. When fertilizings, using a fertilizer made for azaleas will help prevent burning.