How to Get Rid of Fungus on Azaleas

Azalea is a beautiful flowering shrub, grown across the globe for its visual appeal and ability to freshen up and add vibrancy to any space you grow it in.

Plus, it’s very easy to maintain and doesn’t require much to grow and thrive.

On top of all this, the azalea is a very hardy plant and rarely suffers from any kind of issues.

However, when azalea is under stress, due to, for example, unfavorable environmental conditions or being damaged, it becomes less likely to stay healthy.

In this condition, azaleas become vulnerable to various infections and diseases, mostly of fungal nature.

This can be very frustrating for the gardeners and homeowners who are growing azalea, but, fortunately, there are ways to deal with these issues.

Below, I’ll explain what types of these diseases are the most common and how to get rid of fungus on azaleas.

So, let’s dive in!

How to Get Rid of Fungus on Azaleas

Fungus on Azaleas.

Azaleas can suffer from several different fungal diseases. Each of them can damage the plant to a varying degree and each of them requires a somewhat different method of treatment.

Some can be dealt with rather easily, while others need more complex solutions and, in some cases, are even incurable and will likely lead to a fatal outcome, as the plant won’t be able to recover.

I’ll list the most common fungal diseases attacking azaleas and explain what you should do to treat them.


Dieback or bot canker is a disease caused by the fungal pathogen Botryosphaeria dothidea. It mainly attacks the woody parts of azalea and commonly starts by only affecting one branch.

Azalea bark and branches succumb to this fungal disease as fungi enter through the wounds on the plant’s surface or through the natural openings.

Once infected, the area around the opening will become dark and this condition will gradually spread along the stems.

The only way to stop the spread of the disease is to prune below the discolored area and get rid of all the infected stems.

In addition, it’s important to remove any material that has dropped around the base of the plant to avoid reinfection as spores can remain on twigs and leaves.

Also, make sure to disinfect and clean your tools. In the more severe cases, you’ll have to use fungicide or even discard the entire plant.

Powdery Mildew

[amazon box=”B000UJVDXY”]

Powdery mildew is another common issue you may face when growing azalea.

It mostly affects the plants during the fall, leading to a white, cottony, and powdery buildup on top or under the leaves, as well as yellow misting.

The affected leaves may sometimes even completely drop off the plant. The powdery mildew is rather difficult to treat.

Once the infection has already gained a foothold on the plant, your only course of action is to use fungicides designed specifically for use on azaleas.

Of course, the best way to fight powdery mildew is to work on prevention and stop the infection before it even happens.

Look to always plant your azaleas in an area with decent air circulation.

Also, regular pruning will additionally improve circulation, prevent moisture accumulation, and provide more sunlight for the plant.

Creating these conditions will significantly reduce the risk of powdery mildew infection.

Leaf Spot

Leaf spots on azalea can be caused by various fungi pathogens, including Septoria, Phyllosticta, Cercospora, and Colletotrichum.

This disease can be recognized by dark, misshapen spots on the leaves. Leaf spots can also cause leaves to fall off and stunt the growth of the entire plant.

Typically, leaf spot is not a too serious issue, nor can it significantly damage the plant, but it does present a nuisance and ruins the visual appeal of azalea.

The treatment of the leaf spot involves removing the infected leaves to stop the spread of the infection, munching around the base of the plant, and avoiding overwatering the plant and damaging the roots.

Also, you should regularly monitor the soil pH level.

If the infection is not dealt with on time, it may become more severe and, in that case, you may have to use fungicides such as Chlorothalonil or Copper Hydroxide.

Leaf Gall

Leaf gall commonly appears early in the spring as the new azalea leaves begin to grow. The affected leaves will become malformed and you may notice pink or white spores.

Eventually, leaves will begin to change color and turn to place green or white. Ultimately, as the disease progresses the leaves will drop off.

All the leaves that fall off need to be gathered and destroyed to prevent reinfection.

The infected growth commonly can be picked off and removed but, in more severe cases, you’ll have to apply fungicides such as Chlorothalonil or Mancozeb.

Root and Crown Rot

Besides leaves, fungi can also attack azalea roots and crowns.

These rots, also known as water molds, attack the plants in the area around their base and can frequently lead to the death of the plant.

The infection is caused by the Pythium and Phytophthora fungi species which commonly appear in soils that are overwatered and with poor drainage.

As this disease is very serious and difficult to treat, it’s best to focus on prevention.

Make sure that the soil you plant your azaleas in is loose so it can provide good drainage and doesn’t get waterlogged.

You should also avoid planting the azaleas too deeply, or at least not deeper than they were in the nursery.


Azalea is a wonderful addition to every home and as they’re bred to be disease-free, they’re rather resistant to various health issues.

However, like all plants, azalea will experience fungal infections occasionally, especially if there already is an existing problem making it vulnerable or if the conditions are unfavorable.

Some of these diseases are very difficult to deal with, and some can’t even be cured, especially if the infection has room and time to progress.

So, it’s essential to work on preventing these problems, regularly monitor your azaleas for early signs of the diseases, and react as soon as possible when you notice a problem.

Melissa Johnson
Melissa Johnson

Hello, I'm Melissa, owner and author of this website. I hope my article was able to help answer your questions. If you want to learn more about me, click the home icon above.

Companion Planting