I have a potted Mandevilla which I brought into the house for the winter. It seems to be doing well. At first it dropped a lot of leaves, but now there are new leaves and growth and it looks pretty healthy. The other day I noticed that one of the "branches" seems to have split down the middle and has white fuzz on it. Is this some sort of disease or nothing to worry about? I was really hoping to keep this plant alive so that I can place it out on the patio in the spring and have it flower again. It was an extremely healthy plant and bloomed way into the fall.
In most cases the plant can fight this off, but to be sure, I would recommend rubbing peroxide on the area to get rid of this. There won't be much further action necessary after this. I would also recommend letting the soil dry out slightly before each watering, so that the issue doesn't continue.