Root rot

Root rot is a disease in plants, in which the roots of a plant rot and decay. Root rot is a disease in plants, in which the roots of a plant rot and decay. Root rot is seen in both indoor plants, such as houseplants, and in outdoor plants such as trees. It is more commonly seen in indoor plants. Plants' roots are not typically visible as they are below the surface of the soil, so the symptoms of root rot are often only apparent when the disease is advanced. Roots of plants affected by root rot may turn from firm and white to black/brown and soft. Affected roots may also fall off the plant when touched. The leaves of affected plants may also wilt, become small or discolored. Affected plants may also look stunted due to poor growth, develop cankers or ooze sap. Prolonged root rot may lead to death of the plant. In extreme cases, plants affected by root rot may die within 10 days. Root rot is usually lethal although it is treatable. An affected plant will not normally survive, but may potentially be propagated. Root rot is primarily caused by poor drainage of damp soil, overwatering or a poorly functioning root system. Prolonged exposure to excess water causes waterlogging, which interferes with aeration of the roots, leading to low oxygenation and decay. Planting in a dense soil, such as garden soil, can also lead to root rot. Rot can spread from affected roots to other ones. Excess or insufficient light and fertilizer can also increase the chance of a plant developing root rot. Aside from waterlogging, many cases of root rot are caused by pathogens, such as the water mold genus Phytophthora; particularly the species P. cinnamomi. Other commonly responsible pathogens include Pythium, Rhizoctonia, and Fusarium. 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. The wet environment of waterlogged soil promotes the growth of these fungi, allowing them to cause the disease. Garden soil often contains spores of pathogens so it is not advised to be used as a potting medium for indoor house plants.