Question
I have a 5 foot tall cactus. One of my cats recently
defecated in the dirt.I cleaned the dirt,
have covered with aluminum foil and barricade the pot from cats.
The skin surface of the main stem is turning black, up about
20 inches.  My water meter also says the soil is damp.

Any suggestions would be appreciated. I have thought of cutting the top off, lettingit dry a couple weeks
and replanting.  But if I could save the whole plant
I would like too.
Thank you for your service.
KR  

Answer
Dear Kathie,

I don't think the cat had anything to do with it. You should let the soil dry out between waterings so that your water meter doesn't read damp. If the bottom 20 inches of the plant is black, you need to take a cutting to save your plant.

Make a cut about 6 to 8 inches above the black part. If you see black or brown spots, clean the knife or saw (which ever you prefer to use) with alcohol and make another cut about 2 to 3 inches about the previous cut. Repeat until there is no more spots.

Let it dry out for at least 2 weeks before replanting and use new soil. Depending on the type of cactus, it will take a couple of months to root. Only water if the soil is dry. Hope this helps, let me know if you need any additional info.

Sincerely,

Greg