I have several 5 year old San Pedro cacti that I grew from seeds. It’s been really exciting to go from tiny sprouts to 8-10 inch plants! I’m a bit worried about how they’re looking now though and wondering if anyone can help?
For the last 1-2 years they’ve developed these brownish yellow areas and it seems to be gradually worsening. They are in a south facing window, so I first assumed it was sunburn, but moving them for a few months didn’t help. They get water a few times per month, usually more during summer.
Does anyone have any ideas or suggestions as to what may be causing this? Any help would be greatly appreciated!