Root rot can affect indoor and outdoor plants, but it is most common in container gardens with poor drainage. Water isn’t the only thing to blame when root rot strikes your plants—fungi is usually the real culprit.
Plants affected by root rot will have drooping, sometimes yellow, leaves and don’t recover after watering. You’ll also usually notice black, water-soaked spots on the stem near the soil line. The condition takes hold in two ways: either the plant is over-watered and the soil stays too moist, causing the roots to actually rot; or a fungus in the soil is activated by excess water and it begins feeding on the plant’s roots. In either scenario, once root rot is recognized, it’s usually too late to save the plant.
If your plant shows signs of root rot, like yellow leaves, carefully remove the plant from the soil to inspect the roots. Healthy roots will be firm and pliable while rotted roots will be black and mushy. If root rot isn’t the problem, a folar disease could be to blame for yellow leaves. If it is root rot, you can try pruning away the affected roots and re-planting in clean soil, but there’s really no guarantee of survival. Adding fungicide to the soil could also help.
Prevent root rot by watering carefully. Do not over-water your plants. Also be sure to use a container plant soil that is pasteurized.