Hi Debbie,

So sorry to take this long to get back to you. I feel your pain. I love my Japanese maple too.  Japanese Maples are truly works of art.

I’m in need of help on what fungus is killing sections of my Japanese Maple. It lost a major branch a year ago and now more this year. What was the cause? Storm? Disease?

The trunk is definitely showing “growths”. Good sign! It is about 5’ high and 6’ in width planted in my front yard at the top of a bank. It’s about 20-25 years old. I’m sick over its condition and expect that it will need to be totally removed. There is a magnolia in the front corner of my lot that is showing some white spots on its trunk. My first thought is that both of these trees have powdery mildew. Read the description below and see if it fits.

Could the maple’s problem be spreading? Who would be qualified to remove the maple if needed? To remove a tree most and anyone can do that! To treat or trim a tree be sure to call a certified arborist.

Japanese Maples are very slow growers, but under the right conditions can live 60-100 years with good care. Don't give up yet! It looks like there are some dead branches on your tree. Remove them with your clippers. Be sure to clean your clippers with some alcohol before and after using them to prevent the spread of any disease. Also, Japanese maples like slightly acidic soil which is not always common in Ohio. You might think of testing your soil. See link below.

Should I wait until fall and then replace it with another Japanese Maple? I love this kind of tree, and don’t have any ideas on who can help and/or remove and replace it. Thank you for your time and suggestions. Hang in there for awhile!

What Causes of White Spots on Japanese Maple?

The causes of white spots on Japanese maple are powdery mildew, leaf spots, and blight. In addition, it could also be the result of scale insects. These would inhibit the plant and cause it to develop little dots of white color.

– Powdery Mildew

If you’re seeing spots on your Japanese maple, your number one thought should be mildew, and that is the exact problem that will attack this plant. This is a fungal disease that’s the most spread in the plant world and Japanese maples are no exception. Being a fungi-caused disease, this one will thrive in humid and hot conditions, and it would develop and cause chaos.

This one emerges when heaps of fungal spores are found in one place where they stay dormant. Often, they come to leaves via air and water and there they stay until perfect conditions are met. This is when they begin to germinate and develop, as they came from another tree that had been contaminated.

This disease is easy to identify, and it is because those spots are easily disturbed, which means they are in a superficial condition. They are easily smudged across the surface just by running your finger through them. What is actually good though, is that this disease won’t do any substantial damage to your tree.

Japanese Maples are so very beautiful

I’m in need of help on what fungus is killing sections of my Japanese Maple. It lost a major branch a year ago and now more this year. What was the cause? Storm? Disease?

The trunk is definitely showing “growths”. Good sign! It is about 5’ high and 6’ in width planted in my front yard at the top of a bank. It’s about 20-25 years old. I’m sick over its condition and expect that it will need to be totally removed. There is a magnolia in the front corner of my lot that is showing some white spots on its trunk. My first thought is that both of these trees have powdery mildew. Read the description below and see if it fits.

Could the maple’s problem be spreading? Who would be qualified to remove the maple if needed? To remove a tree most and anyone can do that! To treat or trim a tree be sure to call a certified arborist.

Japanese Maples are very slow growers, but under the right conditions can live 60-100 years with good care. Don't give up yet! It looks like there are some dead branches on your tree. Remove them with your clippers. Be sure to clean your clippers with some alcohol before and after using them to prevent the spread of any disease. Also, Japanese maples like slightly acidic soil which is not always common in Ohio. You might think of testing your soil. See link below.

Should I wait until fall and then replace it with another Japanese Maple? I love this kind of tree, and don’t have any ideas on who can help and/or remove and replace it. Thank you for your time and suggestions

What Causes of White Spots on Japanese Maple?

The causes of white spots on Japanese maple are powdery mildew, leaf spots, and blight. In addition, it could also be the result of scale insects. These would inhibit the plant and cause it to develop little dots of white color.

– Powdery Mildew

If you’re seeing spots on your Japanese maple, your number one thought should be mildew, and that is the exact problem that will attack this plant. This is a fungal disease that’s the most spread in the plant world and Japanese maples are no exception. Being a fungi-caused disease, this one will thrive in humid and hot conditions, and it would develop and cause chaos.

This one emerges when heaps of fungal spores are found in one place where they stay dormant. Often, they come to leaves via air and water and there they stay until perfect conditions are met. This is when they begin to germinate and develop, as they came from another tree that had been contaminated.

This disease is easy to identify, and it is because those spots are easily disturbed, which means they are in a superficial condition. They are easily smudged across the surface just by running your finger through them. What is actually good though, is that this disease won’t do any substantial damage to your tree. CHECK THIS OUT FIRST.

– Leaf Spots and Blight If your tree does not have POWDERY mildew, look carefully at other issues.

Spots and blight are diseases commonly caused by several other species of fungi. What makes them different from mildews is that these will damage and bite your leaves! This will come in a range of colors, often white in the center and then black or brown as they spread and grow bigger, Maple

leaf spot fungi thrive in moist conditions and are easily spread via water droplets and stale weather conditions. In humid climates, this disease is often taken without any worry, because it usually goes away on its own as soon as the sky clears, and more air circulation is introduced; in short, the atmosphere would clear the air. We did have a very wet spring in Ohio.

– Scale Insects Doubt this id the problem, but look carefully.

If your spots are looking like they’re crawling then you aren’t dealing with diseases, likely this is a pest infestation. This type of maple tree will often be fighting against mealybugs and aphids, both sap-sucking insects that will do a lot of damage if left on your tree unchecked. They would harm the tree in the long run, and the white spots would become much more in their number.

The microscopic beings often cluster together to protect themselves and begin eating your leaves by sucking the life out of them. These insects will poop honeydew onto lower leaves and soil, which can cause the formation of diseases such as sooty mold.

Methods of Fighting White Spots on Japanese Maple

The methods of fighting white spots on Japanese maple are pruning the infected areas, spraying some fungicides, and also placing chemical-free pesticides on the leaves that have white-colored circles. By using these ways, you will fight the issues and keep the plant healthy.

– Pruning

Powdery mildew isn’t harmful, but if you cannot stand the look at it, you can take some action. Maple will react well from partial or complete defoliation of its infected foliage, so you’re free to cut and remove any infected leaves. By doing so, you are getting rid of the damages that were on your tree, and they will no longer contaminate the rest of the leaves.

– Spray Fungicides

Another way to tackle this would be to use a general fungicide or a homemade mixture of rubbing alcohol and soapy water and spray the rest of the canopy and branches. This solution will help your maple fight any remaining and future fungal spores. –

Pruning

Powdery mildew isn’t harmful, but if you cannot stand the look of it, you can take some action. Maple will react well from partial or complete defoliation of its infected foliage, so you’re free to cut and remove any infected leaves. By doing so, you are getting rid of the damages that were on your tree, and they will no longer contaminate the rest of the leaves.

– Spray Fungicides

Another way to tackle this would be to use a general fungicide or a homemade mixture of rubbing alcohol and soapy water and spray the rest of the canopy and branches. This solution will help your maple fight any remaining and future fungal spores. And this one is made out of neem oil or any other horticultural oil. What you should do is mix a full tablespoon of these with a gallon of water and spray generously over an entire tree.

The leaves will benefit from being soaked every once in a while, and those compounds will suffocate any insects that the liquid finds on its way. After this, you can scrub the bark and the leaves with some rubbing alcohol solution to make sure no insects are left alive.

If you’ve been dealing with an infection that went too far, then you may see some sooty (BLACK/GREY) mold either on the bark or the container where you’re growing your maple. In short, here’s how to deal with it; you will soon see that no issue has been left because these oils have tackled them problem.

As this isn’t a tree disease, but a superficial disease of the sap, there’s not much you can do, except clean it off. Just mix some rubbing alcohol or hand-washing soap with water and rub the spots clean. That way you got rid of both white dots and the black spots caused by fungi.

Conclusion

Those Japanese maples are wonderful specimen plants and their leaves are beautiful things of joy, growing in abundance on every tiny branch. What can go wrong is when those leaves turn white, so in conclusion

• If your maple develops white smudges, you should always study the tree to determine what exactly caused those white things.

• If the issue was mildew, and you reacted like you’re dealing with insect infestation, you’re probably going to do more harm than good.

• To prevent diseases from occurring on your maples, you should always apply fertilizers, and fungicides and allow for awesome air circulation, especially in the growing period.

Keep in mind that fungus growing on a tree can be a sign that the tree is decaying or dying. Because fungi feed on organic matter, they are often a sure sign that a tree is nearing the end of its life. Tree fungi come in diverse arrays of shapes and sizes.

Soil Testing:

https://franklin.osu.edu/program-areas/agriculture-and-natural-resources/soil-testing

https://ohioline.osu.edu/factsheet/hyg-1132