Dear Tim, 

thank you for reaching out to the UVM Extension Master Gardener Helpline and thank you for including pictures.

I am sorry to read that your Sugar Maple tree is struggling.

I reached out to our resident expert to confirm what could be causing the issue on your tree, and although there might be anthracnose present, that would not be causing the paler leaves in early summer and the thinning crown that you are seeing.

Most likely, something is going on lower in the tree like a canker problem or soilborne wilt disease.

At this point there is not much that can be done but look for any cankers (sunken areas) on the trunks or branches affected.  If you see something on the branch, the branch could be removed.  Any dead branches should be removed as well.

The Verticillium fungus typically attacks stressed trees and plugs up the vascular or water conducting system, resulting in dead branches, thinning crowns, early fall color, etc. Sometimes this disease can kill a plant quickly and other times the tree can 'wall off' the pathogen and recover. It is a waiting game to see what happens. If the tree does die, the area should be replanted with a resistant tree such as an evergreen.

I am including links to information that could be of interest to you.

https://www.missouribotanicalgarden.org/gardens-gardening/your-garden/help-for-the-home-gardener/advice-tips-resources/insects-pests-and-problems/diseases/cankers/verticillium-wilt

https://extension.psu.edu/maple-diseases

https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/maple/branchesdiscolored.html

I hope this helps you with your Maple tree.

if you have any further questions, do not hesitate to reach out to the Helpline again, 

thank you 

kindly

On Saturday, July 4, 2026 9:55 AM, Ask Extension wrote: