Q.HOW TO CURE WHITE SPOTS ON PENCIL CACTUS
I have a pencil cactus that is approximately 6 foot tall and I have over looked the white spots on the branches and trunk. When realized the white spots were not from taking cuttings I found an article that advised putting alcohol on the spots. I have been doing that for about two weeks. Last night the trunk was green and on the bottom of the trunk which I had been putting alcohol on was green (which had been white prior) Now the complete trunk is white. Am I slowly killing it or is this killing the infestation which must have been deep. Please advise me how to proceed. I really don’t want to lose it.
Certified GKH Gardening Expert
I think it looks more like powdery mildew than a pest. You can try Neem Oil, it should help in either case.