Divide and replant overgrown plants when appropriate. Timing of watering also can affect leaf spot diseases. It's best to water early in the day so leaves can dry before night. Stem and root rots caused by fungi also can be a problem in the yard and garden. When a plant has an unhealthy root system, it usually shows up as wilting, stunting or yellowing of leaves.
Infected roots tend to show a brown color with the outer portion of the roots rotting off.
If garden plants are found to have a rotted root system or stems, remove the diseased plants along with some of the soil adjacent to the roots. When pruning diseased portions of plants, especially on trees and shrubs, remember to make the cut in the healthy tissue below the obvious unhealthy area. This is to make sure all of the diseased tissue has been removed. It's easiest to prune after the leaves have fallen so the problem areas are more visible. If allowed, burning is a good way to dispose of the debris, or burying the plant debris is another option.