Root rot is a common plant disease, the symptoms of which include wilted leaves that do not recover, even after a good watering. The lower leaves of the plant will likely yellow or rot and drop off the plant. This is cause by a fungi that lives in the soil, which loves wet, poorly-drained soils.
Prevention is the best method of reducing root rot. Root rot will pass through the entire system of the plant within seven to 10 days, causing the plant to die off. The roots of your plant will look brown and have a soft, mushy texture as compared to a healthy root system that is white and firm. Use pasteurized, disease-free soil when potting your plant. If the pot you are using had a plant that was infected, do not plant it in the same soil and wash out the pot.
By the time the symptoms of root rot are present, it is often too late to save the plant. If you do happen to catch the disease in the early stages, you may be able to repot the plant. Look at the roots; if they look fairly healthy, prepare a new pot. Place new soil into the pot and throw out the old soil. Before placing the plant into the new soil, soak the roots in a 10-percent bleach-and-water solution (one part bleach to nine parts water) for 30 minutes to kill the spores.
Apply a fungicide to the plant to stop the spread of the disease. Soaking the soil in a fungicide such as thiophanate-methyl will control and sometimes kill certain varieties of the fungus spore. Fungicide will work as long as the fungus has not had an opportunity to spread and the roots are not widely damaged.