Question
This may sound crazy, but I have noticed air bubbles coming out of the bark on some of my live oak trees during recent rains. They run down and create a foamy mound at the base of the trees.  I live in north central Texas, and we've had a very hot, dry summer - do I have a problem or not?

Answer
Hi there: I live in NJ and we don't have live oaks here but it sounds like you have one of two possible problems.
#1.Wetwood and slime flux are poorly understood tree disease problems. Wetwood is an internal bacterial infection in the wood of host trees. Slime flux is an external bleeding of sap typically associated with such infections. Concern is sometimes justified as wetwood and slime flux can cause noteworthy debilitating effects on infected trees including some die back or decline, and an inability for wounds or pruning scars to form callus tissue for healing.

Recognition: Wetwood and slime flux are most often recognized by the oozing, bleeding, or fluxing of sap from bark fissures, pruning scars or wounds on the stems or branches of infected trees. Fluxing often occurs in branch crotches resulting from the tearing of tissues at these junctures by excessive branch weight, wind, etc. The oozing sap is usually dark brown, frothy or slimy and foul smelling soon after it is exposed to the air due to the activity of certain bacteria, yeast and other fungi by which it is rapidly colonized - hence the name slime flux. Slime flux, when profuse, characteristically flows downward from its points of emergence, and upon drying leaves a light gray to whitish incrustation on the surface of the bark. Due to its oftentimes highly alkaline nature, slime flux frequently results in the death of turf, shrubs, and plants on which it drips beneath infected trees.Internally, wetwood is typically characterized by dark brown discolored wood which appears circular in cross section and wet or water-soaked. This wet wood is also characteristically malodorous, much like the normally associated slime flux.

There is no known effective control for slime flux.Preventative measures such as avoiding moisture stress, proper pruning and adequate fertilization may help invigorate trees.

#2 You could have a borer in the tree. See if there is a small hole in the tree where the sap flow is originating. If so check with your local Agriculture agency for remedies for borers.
Hope this helps.  Bill