Question

chinese pistache trunk  

chinese pistache   I had messaged you about a week ago regarding my Chinese Pistache " Keith Davey" and the black discoloration at the base of tge tree.  I have attached photographs of the tree and the location at the base of the tree that is a concern.  Please ket me know what you think may have caused this problem and what if anything needs to be done.  It does appear thst this location has healed itself since last spring when it appeared to be much worse and had black discoloration on both sides of the trunk.

Thanks

Answer
Kris:
Sorry about my delay in your answer.  Your photos clearly show this healing area near the soil line.  As mentioned, this area may have resulted from an old injury.  Difficult to say, but I would expect it to be of mechanical origin rather than disease/insect related.  If good tree vigor is maintained,this area will be "sealed off" by the outer layers of bark.  Keep in mind that the dead portions of the heartwood will remain.  Long term, the tree will have a structurally weak area in that spot, making it a bit more susceptible to breakage during high winds or heavy snow/ice buildup on the tree.

Hope this helps,
Steve