mexico-magico said:
Gracias for the help everybody
I´m going to cut the sick portion.
Would this be a good moment to perform a grafting over the cutting?
enteogenic-gnosis I double checked the soil and the bottom of the pot looking for any visible mold or fungic attack but didn´t found any sign yet. Should I remove the whole soil to check roots?:?
In my case this is what happened:
A wash-cloth was left underneath the pot the cactus was, this cactus pot had holes in the bottom of it, and water had drained through the soil out of the pot and on to the washcloth beneath it. Everything looked fine, other than the top of the cactus turned into black mush, and the washcloth beneath the pot had turned black due to some fungi or mold.
I did not remove the damaged top (though I probably should have), I simply removed the cactus and it's roots from the old pot and old soil, and placed it in a new pot with new, clean, soil.
I purchased a new bag of cactus and succulent soil, I added some sand, volcanic stones and perlite to to improve drainage, and placed it into a new and clean pot, I then replanted my cactus into this clean pot with clean soil, and it healed.
It took about a month to fully heal, and has been doing amazing ever since.
It's important that you have very well draining soil, and that you take steps to ensure molds and fungi do not attack your roots. I know it seems counterintuitive to see a problem at the top of the cactus and have its source be the roots, but in my case that's is what happened.
You can see from the pictures that the black mush simply hardened and the stalk began putting out pups shortly after it healed.
It looks like exactly what had happened to my cacti, all I can say is that in my situation, clean soil in a new clean pot did the trick, it healed nicely and has not had any issues since.
-eg