Hello,

After looking at your images with the Acer rubrum ‘Autumn Flame’ It looks like it could be a case of leaf scorch or a fungal leaf spot disease. Leaf scorch typically presents as light brown or tan dead areas between the leaf veins and can be caused by environmental factors such as wind, high temperatures, or dry soil. More information is at this link:

ENH-202/ST043: Acer rubrum 'Autumn Flame': 'Autumn Flame' Red Maple (ufl.edu)

On the other hand, fungal diseases can cause brown spots of varying sizes on the leaves, and the edges of these spots may appear yellow or black. More information is at this link:

Maple Diseases & Insect Pests | Home & Garden Information Center (clemson.edu)

To treat fungal leaf spot diseases, it’s recommended to spray the tree three times at two-week intervals with a fungicide. Suitable fungicides include copper-based fungicides, mancozeb, chlorothalonil, thiophanate methyl, or triadimefon starting when the leaves begin to unfurl in spring. It’s important to follow the label directions for application. More information is at this link:

Maple Diseases & Insect Pests | Home & Garden Information Center (clemson.edu)

For leaf scorch, the best treatment is usually to ensure the tree is adequately watered, especially if the scorching is due to dry soil. However, if the scorching is due to an inadequate or diseased root system, additional watering may not have an effect. More information is at this link:

ENH-202/ST043: Acer rubrum 'Autumn Flame': 'Autumn Flame' Red Maple (ufl.edu)

It’s also worth noting that the ‘Autumn Flame’ variety is relatively resistant to leaf spot, so ensuring the tree is well-cared for and monitoring its environment can help prevent future occurrences.

BEFORE YOU DO ANY OF THE TREATMENTS I MENTIONED ABOVE – 2 OPTIONS:

I recommend that you get a confirmed and precise identification of the problem, I recommend you send all your images by e-mail to the MSU Plant & Pest Diagnostics Lab. The experts there can also provide you with the best treatment options. Their email is <personal data hidden> - Please include your name – The lab will let you know if they need a sample sent. FYI – The lab may also ask for additional images too.

Their website is at this link:

Plant & Pest Diagnostics (msu.edu)

Their Contact Information is at this link:

Contact Us - Plant & Pest Diagnostics (msu.edu)

This link will explain the details on submitting a sample to MSU Plant & Pest Diagnostics Lab:

Submit Samples - Plant & Pest Diagnostics (msu.edu)

OPTION 2:

You can consult with a local certified arborist for a more detailed onsite assessment and personalized advice. To find a certified arborist in your Zip Code go to this link:

Find an Arborist (treesaregood.org)

I hope this helps