We have a beautiful Palo Brea that is about 4 years old. This winter I noticed black spots by spring the black spots were ozing sap.
I have made several calls one to DBG plant hotline, one to the Maricopa Extension and several to local tree experts per recommendation of DBG and Maricopa Extension and internet searches.
I found out that what is occuring is very normal. The sap begins to run in the spring when the tree is ready to leaf and flower. The wood peckers love to peck at the tree and the ants come for the sap and the wood peckers come back for the ants.
Or, hybridization can cause an issue that shows up in the bark and the tree dies a slow death. Unfortnatily you will not know if your tree has this defficiancy until years into its growth.Best practice - keep the tree healthy, water deep (3 feet) once a month during the hot summer and not at all during the winter, practice good pruning during summer months when the tree can heal properly.
Time will tell.
See side panel for recommended reading - Pruning, Planting & Care by Eric Johnson