Leaf Spots on Japanese Maples: 7 Causes and Treatments

26.09.2023 - 16:03 / gardenerspath.com / Kristine Lofgren

Leaf Spots on Japanese Maples: 7 Causes and Treatments

Spots are cute on a puppy. But on a Japanese maple? Not so much.

Not only do spots on the foliage make your Japanese maple look shabby, but it’s your tree’s way of telling you there’s trouble afoot.

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While Japanese maples aren’t particularly weak or susceptible to disease, they are often small in stature.

That matters because a fungal infection that causes some defoliation on a massive tree will likely have less of an impact overall than it will for a small specimen that doesn’t have as many leaves to lose.

So, let’s talk about the things that cause these spots and when they might become something to worry about. Here’s a quick preview of everything we’ll go over:

Make sure you’re familiar with theins and outs of raising Japanese maples before we start our journey here. A lot of diseases can be avoided with proper care.

Make looking over your Japanese maples a regular part of your routine – you will be much better off if you can catch things early on.

No matter the cause, your trees will be far less likely to experience disease problems if you rake up fallen leaves in the autumn and water at the soil level rather than on the leaves.

Let’s look at the ailments that may cause spotting on Japanese maple leaves.

Fungi in the Alternaria genus cause dark brown to black spots on the foliage. These spots may or may not have yellow halos.

If the leaves are heavily infected, they will drop from the tree. In bad infections, a young or small Japanese maple can be completely defoliated.

Since the pathogens that cause this disease thrive in