Hurricane Ian Response: We are responding to post-storm requests where we can do so safely. Please visit the American Red Cross to assist families impacted by Ian.

Ah, the iconic maple leaf! It’s one of the most recognizable tree leaves out there, and it usually looks fresh! The leaves shimmer green in spring before putting on a show and turning yellow, orange, and red in fall.

But what if your maple leaves develop unsightly brown or black spots in summer? Is your tree in trouble–or even a goner?

Take a deep breath! While those spots look worrisome, it’s just tar spot–a fungal disease that isn’t a big issue to your tree’s health. Learn more about maple tar spot and how to help your tree rebound below.

Maple Tar Spot: A Tree Fungus You Can Regulate

What Exactly Is Maple Tar Spot?

There are a couple types of fungi that cause those big brown or black spots on maple trees. They’re all called tar spot, and they most often affect:

  • Box elder
  • Norway maple
  • Oregon maple
  • Red maple
  • Silver maple
  • Sugar maple
  • Sycamore

As with most tree fungi, maple tar is more likely to happen if your area has been getting lots of rain!

When Will I See Maple Tar Spots?

The spots usually start developing in early-to-mid-June. Then, the dots are tiny and light green. So, you probably didn’t notice them.

Around August, those tiny spots become significantly wider and thicker. It will literally look like clumps of tar are stuck to the leaves. You may even see spots on the maple seeds – unless you were smart enough to plant a seedless maple without helicopter seeds.

Do Those Black Spots On Maple Leaves Hurt The Tree?

Maple tar spot is mostly a cosmetic issue. The dots bring down the look of your tree – and can even cause early leaf drop.

But that’s about the extent of the issue. Maple tar spot rarely does any damage to the tree’s health.

Is There A Treatment For Black Spots On Maple Tree Leaves?

If you’re really fed up with the maple tar spot, you can have a certified arborist and pesticide applicator apply a fungicide next spring. This is typically only recommended if your tree continually gets maple tar or it’s a prevalent issue in your area. Most tar spot is considered aesthetic and this method usually isn’t necessary.

Plus, to be effective, the fungicide must cover every single leaf, which can be quite the feat on mature maples. That’s why it’s generally best to treat and apply a maple tar fungicide on smaller trees.

Can I Prevent Tar Spot From Happening Again?

The best way to treat and prevent maple tar involves a little elbow grease! As the leaves fall, rake and destroy all leaves. Do your best to get every single leaf out of the area, which in turn will remove most of the tar spot fungal spores.

Black Spots On Your Maple Leaves? We’re Here To Help!

Related Blog Posts

Leaves In Yard
Lawn Care & Maintenance

Managing Fallen Leaves In Your Yard

Are dead leaves harmful to plants or soil? Here are the benefits of fallen leaves and tips on how to best manage fallen leaves in your yard.
Read More
How To Treat Beech Leaf Disease
Insect & Disease Issues

Is Beech Leaf Disease Impacting Your Trees

Let’s look at this beech tree leaf disease, what causes beech leaf disease, and how to treat beech leaf disease so you can better protect your trees from infestation.
Read More

Sign Up For Free Tree & Landscaping Tips! 

Subscribe to the "The Sapling," the Davey Blog's email newsletter, for the latest tips to keep your outdoor space in tip-top shape throughout the year.

Plus, receive a free instant download of our landscape seasonal checklists when you sign up!

Get In Touch With Us!

We pride ourselves at Davey Tree on providing prompt, professional and personalized service from certified arborists that live, work and engage in your community. Contact one of our Davey Tree specialists for your residential, commercial, utility, or environmental needs.

Let's Find What
You're Looking For!

Davey uses cookies to make your experience a great one by providing us analytics so we can offer you the most relevant content. By continuing to use this site, you accept our use of cookies. View our Privacy Policy for more information.