I have been cleaning, rearranging, and repotting houseplants in my sunroom this week. Warm days here in Michigan are almost unheard of in November, but we have been having them, but today was the last day. It was 77 degrees today! But, tomorrow a high of 54…yikes. I pulled most of the plants outside so I could move shelves and mop the floor. The sun wasn’t hot enough to burn the plants so I left them outside for 3 days. Needless to say, with the predicted low temps., my houseplants are all back inside tonight. I.Am.Tired. While I was moving plants outside, I found this dead cactus. So bummed. What happened to my cactus?

This cactus is petrified.

This old man cactus is rotted and dead.
Rotted cactus
I collect these “hairy” cacti. I love them! They reside on the south sill of my sunroom and love the full sun and heat they are receiving. The key is, I don’t water them often because I have helped more than one of these to their death. Watering them on hot sunny summer days when it is going to stay hot for some time is the only time they get water. I watered this a few weeks ago and it was already getting colder at night. It is warm in my sunroom, but also humid and it succumbed to rot. I should have known better. By the time I found it, it was petrified. I cut it open so you could see the inside. This cactus is beyond saving, obviously, but if you catch a cactus in time, it is possible to save it, depending on the extent of the rot. See how to save a rotting cactus here from my friend Larry Hodgson.
- The hollow dead cactus
- The dead cactus is hollow
Inside the rotten cactus
So what is “rot”? Rot is a fungus or bacteria that attack the plant when the conditions are right. In this instance, I’m sure it was too wet, too cold, and rot ensued. By the time I discovered it, it was petrified and hollow. It was hidden behind another plant and since I don’t water them often, I didn’t notice it. I cut it open so you could see the inside. It looks like a moldy mess, but it isn’t wet. It is dry, black, and absolutely disgusting! Poor plant.
Could it have been saved?
If I had caught this when just the bottom was starting to rot, I could have cut the firm, healthy top off, let it callus over, and replanted it. I wish I had. It is hard to see what’s going on behind all the hair, but I should have paid better attention. Hopefully, with a newly rearranged sunroom, I will better be able to care for my plants as I can see them and get to them easier. Remember, a cold, wet cactus is a dead cactus. Take my word for it.
Have you ever had a cactus rot before?
Have a great week!
Oh, this looks too familiar. Thank you for keeping it simple.
Hi Lynda,
It is all too familiar….. 🙁
Lisa
This is exactly what happened to mine, but it was my first so I wasn’t sure if it was supposed to be hollow (even though that seemed highly unlikely, haha). Thanks for your help.
Isn’t it crazy? They thought it was a fine cactus. I was like….its dead! lol
Lisa