Question
My Zygo Cactus appears to have a disease.  The new growth appears nice and green, but the old growth is kind of grey with raised spots. It still flowers.  How should I treat it?

Answer
Hi Kate,

"kind of grey with raised spots" is not specific enough for me to be able to understand what you are seeing.

Can you email some photos to me at [email protected]? Include a photo that shows the entire plant as well as one that is a closeup of the symptoms you are seeing.

Regards,
Will Creed