Crepe Myrtle Tree
The crepe myrtle trees at my office this year have developed a black coloring on the top 12" to 18" of trunk. The trees are about 6 years old and well established and have never had this problem before. Last year in September, we had a flood in our area and they were standing in about 12" of water for a couple of days. Would this have anything to do with the black coloring or is this a mold that we can spray with a fungicide and get rid of?
Certified GKH Gardening Expert
It sounds like it is either sooty mold or sooty canker. These articles will have more information: https://www.gardeningknowhow.com/plant-problems/disease/how-to-get-rid-of-sooty-mold.htm, https://www.gardeningknowhow.com/ornamental/trees/tgen/tree-disease-identification-sooty-canker-fungus.htm Both can be treated with a fungicide, but if it looks more like sooty canker than sooty mold, the trees may need professional help to recover.