Did you ever get a solution for the black on your citrus trees? I have the same thing happening to my Meyer lemon and clementine trees. I purchased them last fall and moved them inside for the winter. Any help would be greatly appreciated!

We live in Campbell CA and have lost a few trees already (Plum, Cypress, Bottle Brush), and now both of our orange trees are under attack. One is about dead, and the other is showing signs of the same black branch. Seems to start at the tops of the tree and work its way down, although I see smaller signs of the black branch throughout the trees. We have tried deep watering, fertilizer but notthe sure if this is something else. Help! We love the orange tree and dont want to lose this.