Unfortunately, just like most if not all plants can turn white from time to time, Rhododendron’s are no exception.
Thankfully, the causes for leaves turning white on Rhododendron’s are quite easy to identify and treat once you know what to look for.
So here are those causes, what to look for and how you can treat your plant today.
Powdery Mildew
The most easily identifiable cause for white leaves on a Rhododendron will be attributed to powdery mildew.
If you notice a white, powdery substance covering parts of the plant or the entirety of it, then you have a powdery mildew problem going on.
Powdery mildew is a fungal issue that can spread in high humidity, or just be caused by dumb luck as this stuff can spread through the air for miles on end.
Unfortunately it can and will spread very easily so it’s best that it gets treated as soon as it’s been noticed.
Solution
One way you can treat powdery mildew on a Rhododendron is to mix a tablespoon of baking soda into a gallon of water and then spray the affected parts of the plant.
Another way you can treat this is by using effective fungicides such as neem oil to also spray onto the plant.
Both are great options and will get the job done so you don’t have to worry about white powder on your Rhododendron anymore.
Pests
Sometimes Rhododendrons can get invaded by a variety of pests such as Rhododendron borers, lace bugs, spider mites and aphids to name a few.
A lot of pests will feed on the leaves, causing nutrient loss and in turn white or pale leaves.
Spider mites will leave behind a webbing like material so that would be an instant giveaway to those specific pests.
Some other signs you have a pest problem going on include curling leaves, drooping leaves, yellowish leaves, holes, white or black spots and bumps on the foliage.
You may even be able to spot the pests themselves, but it depends on what kind you’re dealing with as there are some that are so small you can’t even see them, just the symptoms that follow.
Solution
The very first thing you want to do when dealing with a pest issue is to isolate your Rhododendron from other plants to prevent them from spreading around.
Now that you have done this, there are mainly 3 different ways you can get rid of the bugs.
One way is to use just water to spray them off the plant.
Another way is to use a cotton swab, dipped in rubbing alcohol to remove them by hand, one by one.
Lastly you can use some form of pesticide or insecticide to get rid of them.
Personally I always seem to use neem oil as it’s great to have around since it’s an effective pesticide and fungicide as well.
I recommend this neem oil if you’re in need of this stuff.
For a more in depth guide on dealing with bugs or pests, check out my article how to get rid of bugs on Rhododendrons.
Low Light
Another common cause for Rhododendron leaves turning white can be caused by low light conditions, or a lack of light in general.
Although Rhododendron’s can grow quite well in shade and actually prefer that most of the time over full sun, they still need to get enough bright indirect light to grow and look their best.
A lack of light can cause chlorosis, which is a loss of chlorophyll needed to complete photosynthesis so you can have those full green leaves.
When a Rhododendron is experiencing chlorosis, you may see the leaves turning white, pale or yellow as a result.
Some other signs of too little light include curling leaves, or stretched out leaves known as etiolation.
Solution
If you notice any of the symptoms listed above, then it’s time to find a new location for the plant where it can receive plenty of light on a daily basis.
With that said, you don’t want to place your Rhododendron in full sun all day, only a few hours a day is ideal.
You want somewhere that gets lot’s of bright indirect light such as under balconies or trees for example.
If you’re growing indoors, then most windows will work just fine.
Just be sure to keep the plant a little bit away from the window to prevent the suns rays from burning the leaves.
Once the light issue is taken care of, your Rhododendron should return to it’s normal color.
Conclusion
So there you have it, the main reasons why you have white leaves on your Rhododendron and the steps needed to correct them and return to normal.
As always I hope you find this useful so you don’t have to worry when issues like these arise.