ROOT ROT, THE ROTTEN CYCLE
Sometimes if a plant is overwatered, it just does not seem to recover afterwards or does not seem to produce the healthy outcome expected. The leaves start getting dull and turn yellow and the whole plant seems to be on a slippery path towards its death as it dries up. You try to correct the watering issue but nothing seems to help. Chances are most people often think that the plant requires more water and they definitely go ahead and add water. This is just adding insult to the injury. It is highly likely that the plant is suffering from root rot.
Root rot is a condition found in both indoor and outdoor plants. It is more common in indoor plants with poor drainage. As the name clearly states, the roots of the plant tend to rot away. This is usually as a result of overwatering or exposing the plant to excess water. It is a very common problem in house plants, and is slightly less common in outdoor plants. In both indoor and outdoor plants, it is usually lethal and there is no effective treatment as there is no way of restoring rotten roots.
Root rot can have two sources, one is a prolonged exposure to overwatered conditions can cause some of the roots to die back due to a lack of oxygen. As they die, they can start to decay or rot away. The rot can then spread to healthier roots and kill them as well, even if the soil conditions are corrected. The problem occurs when the excess water makes it very difficult for the roots to get the air that they need for operation, causing them to decay. To avoid root rot, it is best to only water plants when the soil becomes dry, and to put the plant in a well-drained pot. Using a heavy soil, such as one dug up from outdoors can also cause root rot.
The other source can be from a fungus in the soil. The fungus may lay dormant in soil indefinitely and then may suddenly flourish when the plant is overwatered once or twice. The root rot fungus attacks the roots and causes them to die and rot away. Many cases of root rot are caused by members of the water mould genus Phytophthora. Perhaps the most aggressive is P. cinnamomi. Spores from root rot causing agents do contaminate other plants, but the rot cannot take hold unless there is adequate moisture. Spores are not only airborne, but are also carried by insects and other arthropods in the soil.
You may be wondering what does root rot look like? If the plant is slowly wilting and the leaves are turning yellow for seemingly unknown reasons, you will want to check the roots. Remove the plant from the soil and feel the roots. One does not have to be an expert to realize that they are rotting away. The roots affected by root rot will look black and will feel mushy and unhealthy. Affected roots may literally fall off or wither from the plant when you touch them. Healthy roots may be black or pale, but they will feel firm. A plant with root rot will not normally survive, but can often be propagated so it will not be lost completely. It is advisable that plants with root rot be removed and destroyed.