what is causing this bark disease on my peach tree?

Asked July 19, 2017, 6:42 PM EDT

hi! the tree is ~12 years old. the fruit from it is very nice. there is minor damage to the bark at the trunk, from a lawn mower - ~20-30% of the bark is missing. but no fungus, scale, etc at its base. the photo is from a dead branch i recently removed from the tree. the scale is light gray/greenish in color. there's a little sap in places. the problem was only noted recently - i just moved here this past november. what can i do to treat it? there's lots of other branches on this tree like that, but with leaves and fruit still growing. but not for long, i am sure... (crappy cell phone pics; i can get better/more detailed if you can't identify this from these pics.) thanks! doug s.

Frederick County Maryland trees and shrubs fruit peaches trees

3 Responses

The patches of light gray/greenish color are lichens. These are a combination of fungus and algae. They do not cause tree decline. There must be another cause for the dieback of those branches. How does your tree look overall? How does the canopy look? You mentioned that the tree has damage to the trunk from a lawn mower. A physical injury like this can cause dieback of branches, because it interrupts the flow of water and nutrients. This may be the cause of the dead branches.


hi! thanks for your reply. overall, the tree looks ok, but i am worried that other branches look like they may be experiencing the same issues. please see pics; and what i might apply - to the branches, and to the trunk thanks again, doug

It looks like there might be borer damage at the base of the trunk. The oozing sap coming from the trunk (called gummosis) is one of the symptoms of peach tree borer damage. These insects can come in when the trees are stressed (such as from the lawn mower injury). Here is more information about these borers: https://extension.umd.edu/hgic/shade-tree-borers

There might also be some black knot fungus affecting the tree. There really is no effective cure for this and all you can do is prune out the infected and decayed stems. https://extension.umd.edu/hgic/black-knot-trees

Peaches are challenging to grow in Maryland due to many disease and insect pressures. It really takes a regular regimen of pruning and spraying to keep the trees disease/pest free and producing clean fruit. The following web page includes our recommendations for care of stone fruits. We recommend following the Virginia Tech Home Fruit Preventative Spray Schedule, a link to which is included on this page: http://extension.umd.edu/growit/fruits/stone-fruit-care-fertilizing-fruit-thinning-harvesting-spray-...

The damage at the base of the trunk is not something that can be treated or fixed. Eventually the tree will decline from this damage. It looks like you are getting wonderful peaches now, so enjoy them! Keep mulch away from the base of the tree trunk, water the tree during periods of drought, prune out dead/diseased branches, and review the recommended spray schedule for dealing with common diseases/pests in peach trees.