Friday I brought home a gorgeous and enormous philodendron selloum that had just been unloaded from the delivery truck (oops. Now I know to avoid brand new stock). Saturday night, I noticed a tiny stem going to mush. Sunday, emergency surgery, removing 2 outlying clumps because of stem rot. The roots seemed strong. Monday, I removed another small clump. Tuesday, a new leaf unfurled from the main trunk, but it seems unusually thin.

The leaves and stems of the primary trunk have been unaffected. I've coated all pruned tissue liberally with cinnamon or cinnamon-canola paste. It's under bright 5000K lights, in a well-ventilated area, in a well-draining mix. Unfortunately, it's been raining all week and the indoor humidity is in the 60% range, but there's nothing I can do about that but wait for the rain to pass and humidity to plummet back to normal levels. Obviously the plant is in quarantine. I do understand that survival chances are nil if it's systemic rot instead of only foliar, but the articles I've found don't say how to tell. I suppose if it survives the week, then it has a chance...?

Does anyone have any experience bringing a philodendron through an infection like this successfully? The remaining plant looks strong (but for the thin new leaf), but I've never dealt with anything like this before. Thanks in advance.