Too much water can cause some plants to rot and too little water can stress a plant enough to cause premature leaf drop and, eventually, death. Adequate drainage for the plants roots will reduce the chances of fungal problems. When you buy a plant at a nursery, there probably is some peatmoss in the soil mix and orchids are often potted in pine bark or tree fern. These soil amendments are good to grow certain plants in, but they all break down after a year or so. Sanitation is a must in an IPM program.
Unsterilized tools can transmit viruses and fungi from one plant to another.
For example, in Florida unsterilized pruning saws are transporting a fungi that is fatal to Phoenix palms. Weeding is another important method of sanitation. Not only does it look better, but removing unwanted plants can also remove a potential source of food for harmful insects such as White Fly, a minute fly that feeds on the sap of plants. In South Florida, some plants that we consider weeds are the primary host to the types of insects that you would not want attacking your favorite plants. These are some of the things that an average homeowner can do to develop a fairly sophisticated IPM program for the garden.