Ugh! Sorry to hear about it. I'm glad your other ones are doing well. I'd be suspicious of root rot. If it was mine, I'd dig it up and look at the roots to see what's going on. I'd hack off and discard that upper portion, but if the roots looked good I might air-dry it for several days and replant it somewhere else.

Do you think there was an issue with the automatic irrigation?? I wonder if there was a leak in the line, or the emitter broke or came off? or something like that?? Just wondering really. I don't have any of my many (too many, LOL) cacti on drip irrigation, mostly out of fear of a malfunction.

I'm really glad your other cereus are doing well, that's great. I have quite a few from plants, and now some nice 14 inch seedlings from seed (I know, I just can't stop!). They all get water once every day days when it's hot, and none at all (from me, anyway) when it's not.

Let us know what you do, what you decide, and how it works out. Good luck!

Take care,
Grant

I checked the line and I even have a water gadget that tests the soil/moisture/etc...no luck on it. I will take a look at the roots though, good idea. I think for now I'll hack off the gross pieces (they are very soft, ick) and maybe see if the healthy part will be happy somewhere else. I have a 4 foot tall euphorbia ingens still in the nursery planter that would look pretty sweet over there. When did I become such a nerd? ;) Thanks for the tips Grant!

Good luck--let us know what you discover and what you decide to do. It's hard to lose such a big cool cactus, so hopefully you can salvage it. I know you know, but folks reading along might not, but be sure to sterilize whatever tool you use to cut off the nasty parts (I just 90% rubbing alcohol, but some folks use 10% bleach). Looking forward to an update or three.

Take care!
Grant

Tools were thoroughly cleaned up before (and after) the big beheading and yes, that's a very good thing to remember!

I chopped off the worst parts of the cactus. On top of that, I got down in there and took a look at the roots, they looked healthy. There was no rot or foul smell. I aerated a little of the soil around it (without disturbing the roots) and put the crushed granite back down. A few days later it isn't quite as yellow anymore and while there are still some brown spots, it hasn't spread. So far so good. Maybe it helped, then again, maybe the peruvian is just showing off for the adorable candelabra tree I planted that day nearby. ;)

I'm glad the remaining parts look healthy. Keep us posted on how it does. I hope it recovers quickly and fully for you.

Thanks for the update, and good job with the Surgery, lol.
Take care,
Grant