Leaf Spot Or Fluoridechlorinesalts

This sort of leaf spot can be caused by several things and without culturing in a lab it’s hard to be sure. It’s also possible with plants that what you are seeing is a combination of problems. Excess build up of fluoride, chlorine or fertilizer salts in the soil is probably the cause. This commonly happens when a houseplant is watered with “city water” that has fluoride and chlorine in it over a long period, and/or when fertilizer salts have been allowed to build up in the pot. The solution for this is to repot the plant, gently removing some of the old potting mix from the roots and putting the plant back in a clean pot with new potting soil. Do not put rocks, shards or other materials in the bottom of the pot no matter where you’ve read that information: it’s bad for plants. After that, water with distilled or well water that doesn’t have fluoride or chlorine in it. Use an organic fertilizer in the future according to directions.