Hi everyone,

I've had this cactus for years, and prior to this year, I had never put it outside during the summer. I've brought it inside a week ago and it's not doing well. What can I do? I would hate to kill my oldest plant.

Thank you! Any insight will help!

to the forum deandrag!
The partial ring around the stem looks like it was damaged at the growing point a while ago; maybe when it went outside? The scarring at the top looks like it might have sunburned during the summer. Either way, the markings are permanent but the plant isn't in any danger. If you can post a closer picture of the top part we might be able to see if anything important is going on there.

Sunburned pilocereus?? I would suggest letting it recover, if you see the dead part spread, cut off the top of it. The cactus may start rotting if the sunburned part gets infected.

The sunburned parts are getting papery. That's a good thing because it means you are past the survive or rot stage. When you put an indoor cactus outdoors, it must be acclimated over a couple weeks to brighter and brighter light. If you had it in a full sun window indoors, move it to a shady porch outdoors. You can slowly move to more and more sun or be happy with the porch. I don't move happy plants in and out every year because its traumatic for them (and way more work than I'm willing to put into the project). For a happy indoor plant, I don't see any benefit.

Most cactus pick up the scars of life's battles as they age (this happens with us humans as well ) . It gives them character
I like to quote that line from pulp fiction where an old battle hardened gangster is talking to a teenager who says "i have character" The old guys says "just because you are a character, it doesn't mean you have character "