Why Are My Azalea Leaves Turning Red?

Last Updated on November 7, 2022 by Stephanie

Its common for old leaves of Azalea plants to change color especially in the autumn. If however, the newly sprouted or even all of the leaves on your plant are turning red this is a sign that the plant is struggling and stressed and should do something to fix the issue.

Stress from the environment is the main reason for the azalea leaves to turn red. It could be due to a variety of factors, but mostly over exposure to sunlight or excessive watering. Azalea also produces an anthocyanin red pigment to shield itself from stress-related causes.

In this post, Ill walk you through possible reasons for why your Azalea may be feeling stressed, and provide some suggestions to help you make the situation better.

Causes of Azalea Leaves Turning Red


If a plant is stressed due to any reason, it is likely to produce anthocyanins to counteract the stress. Anthocyanins are purple or red pigments that play a variety of functions in protecting plants from harm. The precise mechanisms behind how anthocyanins help protect plants are a mystery and still being studied. (Source: DePauw University)

Anthocyanins have been proven to shield plants from UV radiation in sunlight, and to increase the efficiency of photosynthesis at low levels of light.

Anthocyanins are also involved to protect plants against freezing temperatures, predators and alkaline soils that are highly acidic or acidic.


Avoid stressing your plant. Maintain it in a steady setting with temperatures that do not frequently exceed 85 degrees Fahrenheit (29degC) and away from hot sources of heat and drafts.

Make sure that your plant gets plenty of bright indirect light, but only a little direct sunlight. Keep it in moist, acidic, well-drained soil.

Leaf Spot Diseases

A variety of fungal and bacterial illnesses can cause yellow, red, or even brown spots form on the leaves of your plant. The spots could be a mix of the various colors, usually brown in the middle, and red and yellow around the edges.

The organisms responsible for the problems vary but the root of the problem is usually poor watering practices or excessive rain exposure.

If water contaminated with bacteria or spores splashes on the leaves of a plant for instance, during heavy rain , or when watering the plant in a negligent manner the plant, the bacteria can be able to take over and create problems for your plant.

How severe these illnesses is dependent on the specific organism that is at risk. The red color can be a signal that the plant you have is struggling with against something. If you notice spots that are yellow or brown this could be an bacterial or fungal leaf spot disease.


Certain fungal leaf spot conditions are treatable by fungicides, however other such as leaf spots caused by bacteria are nearly impossible to cure once theyve become a problem. Its always better to avoid these illnesses rather than trying to treat them.

The most effective way to prevent diseases in the plants of your Azaleas is to clear fallen leaves and other debris from the pot of your Azaleas, since bacteria and spores live there, just waiting to get into your plant.

Be careful not to splash water on the stem and leaves of the plant. Be sure to protect it from rain , and, in the best case to water the plant from beneath. This reduces the chance of getting sick, but also improves the strength of the roots of the plant.

Azalea flowers

Too Much Sun

Azaleas thrive in areas that has shade and light and dont receive excessive direct sun hitting their leaves.

If too much intense sunlight hits the leaves of a plant and leaves, it affects the functions of the leaf and cell walls begin to shrink and cause the leaves to shrink and then fall from the plants.

If the damage from sun isnt too severe For instance when the plant is being burned for an hour or more for a prolonged period of time, you could notice an issue - the leaves turn dark red, before drying and turning brown.

Anthocyanins are the plants main ingredient that shield the leaves from harmful UV rays that are produced by sunlight, creating a red-colored appearance.

But, if the damage to the sun is extremely severe, such as many days of scorching sunlight of summer, your plant may not be able to survive. It doesnt have the time to make its own anthocyanin sunscreen and the leaves are likely to burn - and then turn dry and brown, before falling off the plant.


Make sure to keep the Azalea in a spot which receives lots of indirect but bright light and at least two hours per day of direct sunlight hitting the leaves.

Do not place your plant on a window or close to a window as it is prone to sunburn - the glass in a window increases the intensity of suns rays, meaning that they can quickly scorch your plant.

If you place your plant in a spot that receives direct sunlight, ensure that it is at least a few feet away from the window.

Nutrient Deficiency

Azaleas arent heavy feeders however they require various nutrients, such as phosphorous, magnesium, nitrogen, and iron to stay healthy.

If the levels of these nutrients are not sufficient The plant may display different symptoms, including slower or slow growth, which could be yellow, pale red, or dark green.

One thing to keep in mind when you are growing Azaleas is the fact that they require acidic soil in order to take in nutrients efficiently.

The leaves of your Azalea are becoming red at the edges or are appearing in spots, the issue may be due to one of the following deficiencies in nutrient levels:


The majority of deficiencies in nutrients are simple to fix by feeding your plant more of the pertinent nutrients. It isnt always easy to identify the nutrient that your plant is lacking, however. Another option is to have your soil tested by a lab and provide you with an analysis of the nutrients present in the soil.

If you decide to go this route its crucial to keep in mind that Azaleas require acidic soil in order to absorb nutrients. the soil may be brimming with nutrients however if its too acidic, the plant will not be capable of absorbing it effectively.

As Azaleas prefer soil that is acidic with pH 4.5 to 5.5 It is recommended to choose an potting mix specifically designed for plants that love acid.

This will make sure that your plant is able to absorb the nutrients that it requires, and you dont have to do anything other than feeding it every year in the spring, and again using an acid-loving fertilizer.

Follow the directions strictly to ensure you arent tempted to feed your plant too much, since this could cause burning to the roots of your plant and create more issues.

In the event that your plants are potted in alkaline or general-purpose compost soil, its likely that youll require acidification. It is possible to use a gentle application of ferrous sulfate in order to reduce the pH. Do not use aluminum sulfate since it can be toxic to Azaleas.

Lack of Light

While they can be found in a shaded position, Azaleas dont do well in heavy shade. If they dont get enough sunlight, they release Anthocyanins that help improve the efficiency of photosynthesis. It is possible to notice that leaves change to deep red and then lean towards the light source closest to them.


Be sure that your Azalea receives minimum 8-10 hours per day of indirect, bright sunlight. If you notice that your plant is tilting toward the light or the leaves turning red to green, shift it to a spot that has more sunlight.

Over or underwatering

Azaleas prefer a consistently well-drained, moist soil that is well-drained and consistently moist. When the soil becomes either too dry or wet the plant can be stressed and the leaves may turn red because of the production of anthocyanins.

In any situation, your plant will show signs of dehydration, such as curly, limp leaves that slowly die. If you observe these symptoms, dont immediately water your plant . If its already soaked it will make the issue more severe!

A plant that is waterlogged can be dehydrated due to the fact that its roots are covered with water, it is unable to absorb anything , even water.


You should water your Azalea after the top two inches of the compost is completely dry. Make sure to check the compost first with your fingers or a moisture gauge, and dont give your plant water when it doesnt require it. Dont water according to a schedule because the needs of plants differ based on the season and the situation.

Should You Worry About Azalea Turning Red?

In short, it depends. If some of the older leaves change color before they fall from the plants, its perfectly normal. But, if the plants new growth is turning red, or all the leaves are changing color is a sign that something is wrong with the environment of your plant or in the way you care for the plant.



Went from an inexperienced gardener to a half-decent one over 10+ years. I cover anything from general indoor plant guides and lawn care, to succulents and flowers. Super happy to share my tips and tricks with you :)