Question
Dear Greg,

I noticed that top part of my moon cactus has dark spots all over and also turning yellow!  I think it is rotten and want to find out what to do to save it?  Also spots are spreading to the fruits (babies)that was growing sides on the top part of moon cactus, can I remove them and plant those fruits separately???  Please let me know and thank you in advance!  

Answer
Dear Susan,

Generally, a "moon cactus" can not survive on its own because in order to make it the color it is, all of the chlorophyll has to be remove from the plant. That is why it is "grafted" onto another cactus, for nutrients. I have included a website that discusses how to re-graft the babies. It is fairly complicated, so you can decide if you want to try. It does sound like your plant is rotting, which is not uncommon with moon cactus.

Moon cactus usually do not live very long for the reasons I mention above. I think the irradiation process that removes the chlorophyll also damages the plant. Good luck and I hope this helps.

http://www.cactuscollection.com/faqs/index.html

Sincerely,

Greg