New Monstera Leaf Brown Spots. If your plant has brown spots on the leaves which are surrounded a yellow halo around the brown spot this is a classic symptom of a fungus. Monstera turning brown because of sunburn low humidity poor nutrients over-fertilization transplant shock diseases and extreme temperatures.
As I said in the beginning Monstera tend to put out new leaves monthly. Photo Courtesy of Reddit. If your plant has brown spots on the leaves which are surrounded a yellow halo around the brown spot this is a classic symptom of a fungus.
Keep in mind that after a leaf develops it will not change.
Leaf spot shows up as brown or black water soaked spots on the foliage sometimes with a yellow halo around it. When there are a few spots on a leaf and they begin to grow they will eventually join together and become a large blotch on the leaf. They also have seemed to stop growing. Brown spots on the underside of leaves indicate red spider mites.