Had the same issue after a hurricane whole yard of.cactus had the spots once i moved plants to a drier location they stopped the black spots and some corked some rotted and had to be cut out Too much water too much humidity and you may want to male your soil even more inorganic material and of course very easy draining . For me in the south gulf of mexico - 50%perlite/25% very course sand or pea gravel/ 25% high quality soil. I also add meduim lava rock to the bittom of the pot before adding soil mix to aid in airation and drainage in addition to adding more holes for water and moisture to evap or leak out. All my new growth is spot free. Worse case scenarioun un pot and let the plant roots dry out and then repot without watering for a while.
I dont think the edema is viral , i gave it to all my cacti on accident there was a homemade spray I was using for spider mites and I have been using the spray for a couple weeks on all sorts of plants including my cacti. But also more sensitive plants but what day i watered , sprayed that night and i forgot to turn on my fans and all my cacti got those giant swollen black spots that turned brown and corky after a while i think i blocked the pores with the spray and between watering , the high humidity and spray, cells burst from not being able to let water out
@@SkillCult I also had been fertilizing a few and my biggest got uppotted a few days before but the common factors between all of them were being watered being sprayed and high humidity with no air flow for the night it happened, the spray had never bothered them before it was just Castile soap with a Little isopropyl and a little hydrogen peroxide
Had the same issue after a hurricane whole yard of.cactus had the spots once i moved plants to a drier location they stopped the black spots and some corked some rotted and had to be cut out
Too much water too much humidity and you may want to male your soil even more inorganic material and of course very easy draining .
For me in the south gulf of mexico
- 50%perlite/25% very course sand or pea gravel/ 25% high quality soil.
I also add meduim lava rock to the bittom of the pot before adding soil mix to aid in airation and drainage in addition to adding more holes for water and moisture to evap or leak out.
All my new growth is spot free.
Worse case scenarioun un pot and let the plant roots dry out and then repot without watering for a while.
That black rot is all edema or something like that
some of mine had similar black spots and my friend said it was from getting to much water but idk
I dont think the edema is viral , i gave it to all my cacti on accident there was a homemade spray I was using for spider mites and I have been using the spray for a couple weeks on all sorts of plants including my cacti. But also more sensitive plants but what day i watered , sprayed that night and i forgot to turn on my fans and all my cacti got those giant swollen black spots that turned brown and corky after a while i think i blocked the pores with the spray and between watering , the high humidity and spray, cells burst from not being able to let water out
thanks someone else said something similar. I have thought before that it may have something to do with water or fertilizing excessively.
@@SkillCult I also had been fertilizing a few and my biggest got uppotted a few days before but the common factors between all of them were being watered being sprayed and high humidity with no air flow for the night it happened, the spray had never bothered them before it was just Castile soap with a Little isopropyl and a little hydrogen peroxide