Thank you! I cut the top off and it looks great. There was black all the way down to the bottom callus, 3.5'

IMG_8904.jpeg IMG_8901.jpeg We planted this 4' cutting in a terra cotta pot with well draining cactus mix soil. Did water sparingly after planting the cutting. Black tissue formed within one day, and then white spots on top of the black. Do I need to cut it in half to save it? Both above and below ...