I have owned this cactus for over five years, and it has thrived very well. I keep it indoors in the heat and I never overwater, but it is deflating rather rapidly. There is no sign of decay, however, I have never changed the soil. I just ordered special soil that’s extra gritty and dusty like the Arizona dirt, and that will arrive soon. If anyone can offer advice on what could be happening to it, that would be greatly appreciated :)
It is often caused by root death, so I would check them first. Dead roots does not always kill the entire plant immediately, it just slowly desiccates and it can take years before it dies. I recently discovered that the roots on one of my own rigidissimus have died, and I know that it must have happened in 2014. I think it is too late for that one, but there is still living tissue inside it.
thank you so much! I replanted it in a bigger container with more soil so see if it may recover, but its roots look pretty bad.
Dead tissue should preferably be removed before repotting (and the rest allowed to heal before repotting). I found living roots inside my rigidissimus, and they would not have been able to push through the dead tissue beneath them if I had not removed it.
