Question
I have a large barrel cactus (15 inches tall X 12 inches wide)that is dying since I brought it inside for the winter. It had a bad odor, and then I noticed that it is getting soft near the upper one-third of the plant. The lower two-thirds seem firm still.  I have had the plant for about ten years. It has bloomed regularly and has been a good plant.  Can this cactus be saved?
Thank you for your help.

Answer
Mary,

It is better that it is rotting from the top down rather than the bottom up. You can try cutting the rotted parts out of the plant. But being a barrel cactus, it may or may not branch. Depending on the type of barrel cactus it is, it may have very stout spines. If that is the case, it may be very difficult to cut. Please be very careful.

You can also just leave it be. If it is frost damage, it may heal on its own. Just don't water it for a while, as that will contribute to the problem. Sorry for the bad news.

Sincerely,

Greg