I'm growing ruby red swiss chard (the plants are a few inches tall) and I noticed that the leaves are sort of splitting in the middle, like the leaves are literrally sort of ripping in half in some areas. Another one has these dark unidentified spots on them that I don't understand. I'm growing them in a long rectangular container with sand, earthworm castings, mushroom
compost, top soil, peat moss, perlite, and leaf mulch. I had previously harvested some french breakfast radishes a month ago from the container before transplanting the chard into them. Didn't fertilize the chard until a few days ago though (I fertilize with earthworm castings, I don't know how much I should apply but i usually just give it a heavy sprinkle and water it in, I hear you don't have to use very much but if you do it won't hurt the plants). I feel like theres something that theyre lacking, even though other than that they look pretty healthy.. anyone experienced this before?