Cactus Advice Request.

Question

Having proudly acquired a Blue Columnar Cactus just over a year ago (in July 2022), I recently discovered your interesting Gardening website! 🌵 I was wondering if you might kindly be able to provide a little advice regarding an issue with my plant… 🤔 As indicated in my 3 enclosed photos, it contains 7 stems of different sizes, 5 of which appear to be in good health. However, 2 of them do not, including: – one that is surrounded by the others (with a brown-coloured wound)… – another that has a white-coloured mark, does not seem to be growing and has remained dark green (whereas the 5 healthy stems have a combination of light and dark green)… A few days ago, I carefully applied a few drops of hydrogen peroxide on the problematic areas (visible in my photo #3), but have yet to see any satisfying results… Any useful recommendations would be most appreciated!

Answer 1

We didn't get the photos, unfortunately. It could be disease or mechanical injury. These articles should help:

https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/cactus-going-soft.htm

https://www.gardeningknowhow.com/ornamental/cacti-succulents/scgen/how-to-deal-with-succulent-pests.htm