does this look like canker or just injury?
We have a weeping cherry tree that is oozing a large amount of clear and gummy sap from the trunk. Most of the trunk of the tree, up to about 5-6 feet where the branches begin and the exposed base of the tree are oozing. The branches don't seem affected at this time. (The branches might be grafted but I am not certain) Except for the oozing sap on the trunk the tree looks healthy otherwise. When I remove the gobs of sap, in some places the bark looks normal. In other places the bark is raised. If I slice through the raised part with a knife the bark underneath looks brown, but alive. We are hoping you can help us identify what may be causing this, and what remedial action we might attempt. Thank you for your help
Cherry trees can exude sap/gum due to any type of stress such as pruning cuts, wounds, cankers, or possible insect pests such as the peach tree borer. If you see some 'sawdust'-like material (frass) on the ground below the holes or in the sap exuding from the holes, it could be an indicator of borers. There are no chemical controls for the above.
In general cherry trees are not long lived trees. At this point all you can do is prune dead wood and prune damaged areas back to healthy tissue. If this is in the main trunk this is not possible. The best recommendation is to keep the tree watered during dry periods. Make sure mulch is no thicker than several inches and away from the trunk. If the canopy looks good all you can do is enjoy the tree and it sounds like you may have to consider removal in the future.
Here is more on ornamental fruit trees https://extension.umd.edu/sites/extension.umd.edu/files/_docs/programs/hgic/HGIC_Pubs/TreesandShrubs...