Hewitt's Garden Centers > Questions > Hello,Our magnolia tree’s bark has turned black, top to bottom. There are some spring buds but I’m thinking it has a fungus or some kind of sooty mold. Is there something we should treat it with?
It could be a sooty mold which grows in the sweet sap that oozes out of the bark due to small wound from insects attacking the bark. Spraying for the insects will stops the wounding and stop the mold. Insecticidal soap may work if this is the case. Spray thoroughly once a week for three weeks.