Older night blooming cereus leaves have brown spots
New growth is shiny and green; older growth has small brown spots on leaves and along "spine" and in places long the edges of the leaves. Plant is currently in a west window and has not been re-potted in some time. I am in NY so the plant lives indoors. Since it is fall, should I avoid repotting and fertilizing, or should I give that a try? (am not able to upload photo, not sure why)
Certified GKH Gardening Expert
You should definitely repot that into a cactus or epiphyte soil. It looks like it has a mild infection, which will likely be due to the potting soil, and being too wet for too long.
Make sure when you water in the new potting mix that you replace 1/4 of the water with peroxide. This will help kill off any remaining infection on the roots.
This article will give you more information on the care of these: https://www.gardeningknowhow.com/ornamental/cacti-succulents/night-blooming-cereus/night-blooming-cereus.htm
When you say peroxide, is it peroxide I buy at the drugstore? Or is it the stronger peroxide that is carried by hydroponic supply stores?