Azalea Leaves Turning Red (Common Reasons with Best Fixes)

It’s hard to picture spring without many beautiful azaleas popping up here, there and everywhere. All those amazing fragrances are streaming from abundant patches of yellows, pinks, oranges, reds and whites.

What’s more, they are extremely easy to grow and maintain. One of their minor flaws is their potential to start forming red leaves instead of lush green ones.

Do you know why are azalea leaves turning red a thing to worry?

Of course, if they start turning red in the fall/autumn, sit back and enjoy because that’s what they do before they shed. However, the rest of the time it could indicate a deeper problem for your azaleas.

It can be a sure sign that it is struggling with either one or multiple of its growing conditions. In this article, you will discover how to identify the problem and fix it so your azaleas can once again thrive.

Azalea leaves turning red 

Let’s dive in, shall we?

Azalea Leaves Turning Red: 8 Possible Reasons with Solutions

There is a whole range of reasons that could make your azalea leaves turn red. They could be getting prepared for the fall/autumn.

During this time, many trees, plants and shrubs go through the process of shedding. Their leaves can turn red, yellow and even brown before they shrivel up and die.

If your azaleas leaves begin to show signs of red leaves when it isn’t this time of year, there could be underlying problems causing this to happen. Let’s look at what they are and what you can do about each issue to correct it.

Azalea Leaves Turning Red: 8 Possible Reasons With Solutions

Stress (Anthocyanins)

When plants are subject to certain stressors, they produce a pigment called Anthocyanin. Depending on the pH of this anthocyanin, it can turn a range of colors, such as red, purple, blue, or black. Research has shown that these pigments help to protect the plant.

It is still unknown how it works. The protection does offer, though, against UV rays in sunlight. Additionally, when lower amounts of light are present, anthocyanins help increase the photosynthesis process’s effectiveness.

Furthermore, the pigments protect against other stressors such as erratic acidic/alkaline soils, extremely low temperatures, and certain predatory pests. 

How to Cure?

These stressors can be counteracted in several ways. UV rays in sunlight can be mitigated by having your azaleas grow somewhere with an abundance of bright, indirect light whilst restricting the amount of direct light it receives.

The soil conditions can always be adjusted by introducing better drainage and a frequent watering schedule. Also, aim to grow your plant somewhere that isn’t subject to high winds or extreme heat and colds. Use shading and windbreaks where possible.

Leaf Spot Diseases

When an azalea is subject to poor watering techniques and/or heavy rain, small organisms such as spores and bacteria can leach onto the leaves of your azalea.

As a result, they can cause a range of fungal and or bacterial diseases to form.

Once these diseases establish themselves within the plant’s leaves, they can turn them into different colors, such as red, yellow, or brown. They can also cause spotting and ringing.

The latter is more of a smudge in the middle and rings fanning out toward the edge of the leaf. 

How to Cure?

When these types of diseases take hold, there is often a risk that they haven’t been discovered early enough, and the plant dies as a result.

It’s not always the case but taking preventative measures is the best cause of action. Fungicides such as copper hydroxide, copper-based fungicides, thiophanate-methyl or chlorothalonil work best on azaleas in the latter stages of disease development.

If you spot the signs early enough, you can perform some minor plant surgery. Understandably, that sounds scary, but it’s as simple as removing some dead leaves and debris. Diseases love building colonies on stagnant limbs.

Moreover, protect your plants from heavy rains, never water the plant from above and try to minimize overwatering and splashing where possible.

Keeping the plant clean will reduce the risk of diseases spawning in those areas.

Nutrient Deficiency

Azaleas don’t crave large amounts of nutrients to enable them to flourish. But, the nutrients they require to grow efficiently are iron, nitrogen, magnesium, phosphorous, and Manganese.

When azalea doesn’t get enough of these, they can start to show signs of discoloration as a result. Not only can they turn red but also palish green, yellow, and a darker green.

Azaleas require more acidic soil to enable them to absorb their nutrients. If the soil isn’t allowing the azaleas to take up nutrients, deficiencies occur, and these abnormal colors can start to show.

Here is a list of the nutrients azaleas require and their deficiency symptoms. 

  • Iron – Veins stay green, but a yellow color forms between each vein. Red patches or leaf edges. 
  • Nitrogen – Red spots and edges on older leaves. Leaves are going pale and have extremely slow growth. 
  • Magnesium – Red/purple spots forming on leaf tops. Yellow tips and veins.
  • Phosphorus – Dark green leaves turning into deep red/purple spots or lines through the middle.
  • Manganese – The same as iron, only less severe and prominent. 

How to Cure?

The easiest way to determine which nutrient your azalea is deficient in is by taking a soil sample and testing it. This way, you can adjust the nutrients accordingly without guessing.

Additionally, try to get the soil acidity level to around 5-5.5. If the value is too high, it doesn’t matter what nutrients you give to your plant. They simply won’t be able to take any of them in. Using ferrous sulfate will help lower the pH if the potting mix is highly alkaline. 

Sunlight Overexposure

Azaleas don’t like being pelted with direct sunlight. They enjoy some sun, but it’s better to grow them where they can receive sunlight in the mornings and are protected by shades in the warmth of the afternoon.

Ideally, you should plant them where they receive partial shade all day long to have the best of both worlds.

Ultimately, 4 hours of direct sun per day is more than enough. Too much sun will dry the leaves out. In addition, they will begin to curl and turn red and brown if left unattended.

This red color comes from Anthocyanin, the azalea’s defense mechanism against UV rays.

How to Cure?

The simple fix to this issue is placement. If you notice that your plant leaves are beginning to turn red, you can set up some kind of shade cloth or covering.

Alternatively, if the azaleas are potted, move them somewhere where they can receive lots of indirect sunlight and respite from harsher temperatures. E.g.: under a roof, on a window sill, etc.

Azalea Leaves Turning Red

Insufficient Light

Light is one of the most important requirements for any plant, including azaleas. If not enough light is present, the photosynthesis process doesn’t function as effectively as it does with abundant light.

Azaleas will again reach for their magic Anthocyanin stores to better use the current light.

The leaves will start to turn red due to this pigment being released. Another visual sign of light deficiency is legginess in plants. They use all of their energy to try to reach for the sun and focus on growing parts of the plant closest to the sun.

This leaves the lower parts long and spindly without any leaves or stems. 

How to Cure?

A similar solution used with overexposure to light can be administered. Move the plant to somewhere that does receive its daily allowance of indirect sunlight.

If you notice the leaves still turning slight tinges of red, try moving it again until you get the positioning right. 

Spider Mites

A few pests can make the leaves of your azalea turn red. It’s more common that spider mites are the culprits, but aphids can also make a mess of your plants.

These little buggers suck the sap out of the leaves, leaving them without moisture and nutrients. Nutrient deficiency makes the leaves turn red, but the pests are the real issue. 

How to Cure?

You can use a range of products to eradicate these types of pests from your azaleas. Some are natural, and others are harsher in their chemical form. The best products are simple homemade insecticidal soaps. A simple solution can be created by mixing:

  • 2.5 tablespoons of vegetable oil.
  • 2.5 tablespoons of pure liquid soap.
  • 1 gallon of distilled water.

This will give you a whole gallon worth of solution, which you can add to a spray bottle and coat the leaves of your azaleas, both top and bottom. 

Improper Watering

Azaleas are slightly fussy when it comes to the amount of moisture that they receive. They thrive in soils that are well draining but, on the other hand, like it to be moist.

The game with these guys is to keep the balance. Too little or too much water can see it once again to release Anthocyanin as it gets stressed.

As we know, the leaves turn red as a result. Funnily enough, azaleas can show signs of underwatering, but it can be because the roots are surrounded by water.

Waterlogging can prevent the roots from soaking anything up. It can become quite confusing. 

How to Cure?

When it comes to watering, every plant is different in its requirements. The best way to decide when to water your azalea is to stick your finger into the pot beside the stem. If you notice that the top and a half of the soil are dry, it’s a good idea to give it some water.

If you do so and your plant still seems to be producing red-colored leaves, it may be a good idea to report it. Repotting a plant allows you to start again from scratch and clean out any unnecessary debris.

You can give your plant new soil and nutrients and, ultimately, a new chance at survival. 

Fungal Diseases

When an azalea is left to fend for itself for whatever reason, it risks succumbing to certain fungal diseases such as powdery mildew, leaf spot, and root rot. Powdery mildew forms with high humidity and low airflow.

Leaf spots can be caused by a range of issues, like injuries from nematodes, insects, environmental factors, and the toxicity of herbicides.

Root rot can be brought on by overwatering. The most common visual sign of these diseases is the leaves turning red. 

Azalea Leaves Turning Red

How to Cure?

These types of diseases can get nasty extremely fast. The best way to deal with them is by using Fungicide sprays. You can make your own by mixing baking soda with water. You only need about 4 tsp or 1 tbs (around 20ml) per gallon (4L) of water.

Mix it up and fill up a spray bottle with it. Spray on the affected area. Alternatively, opt for store-bought products that include copper hydroxide, copper-based fungicides, thiophanate-methyl or chlorothalonil.

They are the main ingredients that can help wipe out most infestations if spotted early enough.

Frequently Asked Questions (fAQs)

Should you worry about Azalea leaves turning red?

If your azaleas’ leaves turn red around fall/autumn, then there is no problem. They are going through their shedding process. Otherwise, if they are doing so during other seasons, you may have to eliminate what the cause is and correct it before it’s too late.

Should you prune red Azalea leaves?

The best time to prune an azalea is when its flowers begin to discolor and fade. It may be hard to tell if your whole plant is covered in red leaves. As a rough guide, though, it’s safe to do so around spring or early summer. If the plant is suffering, try to correct the ailment until these times to avoid shock.

Do Azalea Leaves turn red in the fall?

It’s not uncommon for an azalea to form bright green to glowing orange and red colored leaves during the fall. These beautiful plants are one to put on a show at this time of year, so sit back and enjoy it while it lasts.

Why is my Azalea turning brown?

When an azalea produces brown leaves, there can be several problems that it could be struggling through. Firstly, a lack of water could dry the plant, causing the leaves to wilt and go brown. It could also be suffering from root rot which is caused by overwatering. In the worst case, it could have contracted dieback disease. This ailment can kill the plant within 2-3 weeks of contracting it.


Azalea leaves can turn red for several reasons. More innocently, from the shedding process during fall. As far as damaging symptoms are concerned, certain ailments can also make the leaves red in color.

These can include stress, nutrient deficiency, fungal diseases, improper water, pests/insects, overexposure to sunlight and insufficient light. Luckily, most of these issues can be fixed if discovered early enough.

We hope that this article has been helpful, and we look forward to tailoring more just like this for you soon. Happy growing!

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