We found several leaves with large dead black regions, It looks a bit like bananas when they go bad. The plant is a Janet Craig in an office, there are no insects, and this happened rather quickly. We think that perhaps a door was left open and the plant suffered frost danage. We are in Edmonton. Any ideas.
Yes: it might have gotten too cold. Check for a bacterial infection or other pathogenic disorder by searching online or looking in books on house plants. Won't be able to tell for sure without a lab test but might arrive at a possibility and learn of what remedial action could be possible anyway.
Yes, bacteria could be the reason for the problem. Mu Janet Craig had suddenly gotten a few "black areas" on the leaves a couple weeks ago and I chalked it up to getting dry for maybe too long because the heats been blasting around here due to the very cold temps. I think it did the same thing last year too. The leaves with any black on them were pulled off and I'm watching the soil a little closer. So far, no more black.
