Why Is My Queen Of The Night Wilting/dying

Question

This plant is many years old and about 3’ in circumference. I transplanted it a year and a half ago into a very large pot. It’s root do not bump against the side and I’m sure they don’t reach the bottom. It has flourished in the past in the spot it occupies. This summer it started wilting badly. I thought maybe I overwatered so I withheld water, that didn’t help, so I thought maybe I under watered and I Watered it for 3 days well. It perked up for one day and then began to wilt again. I haven’t watered it for a week and no improvement. He root ball is quite large and heavy, do you have even a clue as to what might be the problem? I don’t know whether to water or not. Please both send private email and post on your site if possible. Thank you. I want to save this lovely old friend.

Answer 1

It is supposed to have a weeping habit. They are from rainforests so they do take more water than other cacti but let the soil dry out a little before watering. It's possible the container is too large and is causing overwatering, so feel the soil with a finger before watering. A moisture meter may help as well.

https://www.gardeningknowhow.com/ornamental/cacti-succulents/night-blooming-cereus/night-blooming-cereus.htm

https://plants.ces.ncsu.edu/plants/epiphyllum-oxypetalum/