|My red banana plant has some black stuff around the truck. in between the leafs. What do I need ?|
|I can't tell from your question whether the tissue of the stem is black or if there is a substance on the trunk that is black. In some plants, including red banana plant, the dark pigmentation is normal and natural. If there is a substance rather than a tissue discoloration, it could indicate insect feeding, or a disease (and subsequent collapse) of the plant. It might even be a reaction to cold temperatures.
Wish I could diagnose the problem but without seeing it, I'd only be guessing. Wish I could be more helpful!