Q: This is a leaf from my indoor Peace Lily plant, can you tell me what you think is causing the leaves to get like this ?
A: This looks like bacterial leaf spot. I think there could be three causes: low light, soggy roots, no fertilizer…..or a combination of all three.
Plants in low light or those that have not been fed recently will abort lower leaves…and as the leaves are dropped they get spots like this.
If the plant roots are often soggy, they rot, leading to inability to absorb fertilizer and subsequent leaf drop.
Spathyphylum is a tough plant in most environments. In mid-spring, take it outdoors to a shady spot. Fertilize it and water it anytime the leaves droop.
I bet it will look 100% better by fall.