thanks for the advice! I'll give it a try and see how it goes!
The brown stuff is a sticky sappish fluid oozing from 4 or 5 spots on the cactus. Maybe it's rotting on the inside and that's the cause of the...
I have just inherited a Ritterocereus pruinosus - Silver totem pole cactus ( I know because the tag was still left in the pot from the nursery)...
