Hello,

Before we proceed, I identified your oak as a Northern Red Oak (Quercus rubra) based on your single leaf image

It sounds like you’re dealing with a common issue that affects oak trees. Let’s explore the potential causes and treatment options:

Anthracnose:

Anthracnose is a leaf disease that causes blotchy brown spots on leaves and makes them crinkle or curl up. It’s generally harmless but can be unsightly.

To manage anthracnose:

Rake and remove fallen leaves in the fall to reduce the spread of spores.

For severe infections, mix 2 teaspoons of concentrated chlorothalonil fungicide in 4 gallons of water and spray the tree surface every 7 to 14 days in early spring.

Other Considerations:

Drought Stress: Lack of water can cause leaves to wilt and turn yellow or brown. Ensure proper watering.

Borer Insects: Insects like the two-lined chestnut borer can make leaves brown, wilt, and fall off.

Root Rot: Root rot can cause browning, starting at the top of the tree.

Treatment: Prune dead twigs and branches during dormancy, increase air and light circulation, and rake and destroy fallen leaves. For severely damaged trees, consider applying an appropriate fungicide to protect new growth.

You stated that you consulted with a certified arborist, and he diagnose the issue as Anthracnose, and he did injections and now you stated that the problem still exists with your red oak tree.

I recommend you send all your images by e-mail to the MSU Plant & Pest Diagnostics Lab for a confirm and precise identification. 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.

MAKE SURE THAT YOU TELL THE LAB THAT THE ARBORIST SAID THE ISSUE WAS ANTHRACNOSE AND INJECTIONS WERE PERFORM AND THE PROBLEM STILL EXISTS

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)

I hope this helps!