This was a perfect plant. This started happening a week ago. All the leaves have gone from bright green to black. Some of the leaves are mushy.
I water this plant once a month.
your plant can't get water from anywhere. give it water more regularly, and put wood chips under it. then it will send a long tap root down into the soil.
This is a very accurate description of what i think the problem is: https://www.ted.com/talks/allan_savory_how_to_green_the_world_s_deserts_and_reverse_climate_change
it also looks like people have been stepping all over it, and crushing the leaves.