Hi Chris,

Thank you for contacting the UVM Extension Master Gardener helpline. It is difficult to determine the most likely reason for your maple tree to suddenly wilt without more information. Environmental stress such as drought or flood damage or a late frost can cause sudden wilting. Verticillium wilt can also cause sudden wilting of leaves on a maple tree.

Environmental stress such as drought, compact soils, flood damage, and winter injury can cause leaves to wilt and turn brown at the tips and margins first, then completely brown. A late frost can cause damage to trees and shrubs, including maple trees. Frost injury symptoms include dying and curling of the newly emerging shoot tips sometimes appearing only on the windward side of the tree. The damage typically appears right away. However, after significant cold temperatures, damage may show up later as wilting and browning of the new growth.

If frost did not cause the damage one of the following may apply.

One possibility is that your maple tree may have been infected by a soilborne fungus called Verticillium wilt. Symptoms of infection include suddenly wilted yellow or brown foliage which hangs on the branches. You can try pruning and destroying infected limbs and disinfecting pruning tools after use. If you have a maple, you can also cut into a suspected diseased branch along the long axis. If you see brownish streaking in the wood, the plant is probably infected with verticillium fungus.

According to the University of Minnesota Extension website, other possible causes for your maple tree to wilt could include stem girdling roots, sapwood rot, branch cankers, and coral spot canker.

Here is some information on how to identify stem girdling roots, sapwood rot, branch cankers, and coral spot canker

• Stem girdling roots: Affected trees often have branch dieback, stunted growth, exhibit poor summer color, change color and lose their leaves early in the fall. Affected trees commonly exhibit water-stress symptoms such as marginal leaf scorch, wilting, sudden leaf fall. A root circling the trunk of the tree may be seen at the soil line.

• Sapwood rot: Dead branches within the canopy. Groups or rows of small (<2 inches wide) semi-circle self fungi along killed branches or on the main trunk. Schizophyllum shelf fungi are white and appear fuzzy on top. Cerrena shelf fungi are white to greenish grey and have concentric rings on the surface.

• Branch cankers: Random dead branches seen throughout canopy. Leaves on random branches wilt, turn yellow then brown during the growing season. Infected branches don’t leaf out in spring. Cankers are brown to black sunken areas on branch that may have cracked bark and discolored sapwood.

• Coral spot canker: Dead branches and twigs, often first observed in early spring. Sunken dark brown area on branch that is often cracked or has a ridge at the edge. Raised cushion-like bumps on affected branches may be cream to orange or red, turn black with age.

I suspect the recent late frost is the cause of the damage and if in good health your maple tree will recover without action.

I hope you find this information helpful. Should you have further questions, please don’t hesitate to reply.

Here is a list of all the links from .edu websites that I have referenced.:

1. University of Minnesota Extension: https://apps.extension.umn.edu/garden/diagnose/plant/deciduous/maple/branchesdead.html

2. Penn State Extension: https://extension.psu.edu/maple-diseases

3. Cornell University: http://www.plantclinic.cornell.edu/factsheets/mapledecline.pdf

4. Michigan State University Extension: https://www.canr.msu.edu/news/verticillium_wilt_refresher

5. Oregon State University Extension: https://extension.oregonstate.edu/news/how-examine-deciduous-tree-leaf-out-problems

6. Iowa State University https://hortnews.extension.iastate.edu/cold-and-freeze-damage-garden-plants

Enjoy Spring,

Jeff Nummelin, UVM Extension Master Gardener Volunteer

www.uvm.edu/extension/mastergardener

No endorsement of products mentioned is intended, nor is criticism implied of products not mentioned. Any chemical recommendations in resources included should be used for informational purposes only as these chemicals may not be registered for use in Vermont.