This corn plant is miserable and needs help. Internet search says it has yellow spot and needs to have yellow parts cut off, I think the canes need to be cut and repotted. I'm not sure where is best to cut and how much to cut, and do I need to completely separate all the plants or can I try to maintain the giant pot? What can I do? All advice is welcome.
The patient: In this large pot there are 4 independent canes that have been together long enough for their roots to be completely interwoven. The leaves have a lot of discoloration and deformities happening and some irregular leaf drop in mid growth (as oppose to bottom leaves dropping first).
The tallest cane is still attached to an old stump that formerly had 4 canes before we inherited it, I assume those are the other ones in the pot. This very long stalk has some strange bump in it's growth, I'm calling it the "belly button." The next tallest cane has some really sickly looking stunted growth but looks to have healthy leaves growing again. The two shortest canes have the least discoloration.
Pic 1 & 2 are different angles of the full pot. Pics 3&4 are the tallest cane still attached to the stump and the belly button. Pic 5 is the tallest independent cane and it's weird stunted growth.
Medical Records: Our office inherited this from a neighbor about 2 years ago, it was pretty healthy when we took it in. I have no idea how old it is, but I know it was originally at the home of an avid plant enthusiast before it arrived at our building, I'm guessing 20+ years. It stays in an office with a North facing window, constant exposure, but that office does not have a lot of foot traffic. Overall, the care has been inconsistent with a handful of us visiting it. It may go 3 weeks without water, or it may get watered twice in a week because the top looked dry to the next person walking by who assumed no one else watered yet. It is in a large pot that I just discovered has a trap door for bottom watering but we have only ever watered from the top, I don't think the soil has ever been saturated.
In addition to the stress from watering inconsistency, it has gotten cold. This spot is drafty to begin with and the heating of that office is also inconsistent and was actually out at some point in the winter. Opposite conditions in the summer but I don't think it ever reached a point of overheating or scorching.