Oozing cherry tree

Asked May 27, 2019, 5:09 AM EDT

I have last autumn had my cherry tree pruned by an expert. I now find it oozing in several places on the trunk. Has this been caused by stress or damage?

Outside United States

1 Response

Oozing or Gummosis is really a general response by cherries and other members of the Prunus genus to damage. It could be caused by an insect borrowing in the bark. Here in Michigan we have 3 specific pests that attach cherry trunks
American plum borer, https://www.canr.msu.edu/ipm/diseases/american_plum_borer and Lesser Peach tree borer https://www.canr.msu.edu/uploads/files/PDFs/Insects/LesserPeachtreeBorer.pdf. These two insects attack the trunk and larger branches.
The Peach tree borer focuses more on the lower trunk. https://www.canr.msu.edu/uploads/files/PDFs/Insects/PeachtreeBorer.pdf. We control these borers with insecticide sprays targeted for when these pests are out laying eggs. Weaker trees are more attractive but not necessary for the insects.
Gummosis can also be a result of a disease infection, usually by bacteria canker https://www.canr.msu.edu/ipm/diseases/bacterial_canker_blossom_blast. You usually see this where branches occur.
I have also seen gummosis as a result of cold injury in the winter or some physical injury.
I often tell people that gummosis is like running a fever. You know the tree is hurting and where but you do not know why.