I have had a peace lily about 4 years. The leaves are turning black, and get really wrinkly. I have cut off leaves like this, and new shoots are coming out. But now more of the leaves are turning black. I’m thinking the plant has some sort of fungus. Can it be saved? Do I toss the plant and start over?
From your brief description, it is likely that your Peace Lily is suffering from root rot. Root rot usually occurs slowly over a period of time and without obvious symptoms until the problem is serious. This is a common problem with Peace Lilies because they wilt so pathetically when they get a bit too dry that most people end up watering too often in order to avoid the wilting. This over-compensation leads to the insidious root rot that occurs out of sight. Root rot is not a fungus or disease. It is caused by not allowing the soil to dry out sufficiently between waterings.
There is no easy fix or cure for root rot. Replacing the soil does not work. Fertilizers and anti-fungals don’t help. All you can do is allow the soil to dry out to the point where your Peace Lily starts to wilt. (Note: If it is already wilted and the soil is wet, then the roots are completely rotted and you should discard the plant.) Then, add a small quantity of water – enough to get it to perk up again within a few hours, but not so much that it takes more than 4 or 5 days to reach the wilt point again.
If the roots are still viable, then allowing allowing oxygen into the root zone via this drying out process will allow the roots to slowly recover. Only after the roots recover will you see significant improvement in plant foliage growth.
I have written an article on Peace Lily care that I will email for free to you (or anyone else) who sends a request to me at wcreed@HorticulturalHelp.com.