Root rot is a condition found in both indoor and outdoor plants, although more common in indoor plants with poor drainage. As the name states, the roots of the plant rot. Usually, this is a result of overwatering. In houseplants, it is a very common problem, and is slightly less common in outdoor plants. In both indoor and outdoor plants, it is usually lethal and there is no treatment.
The excess water makes it very difficult for the roots to get air that they need, making them rot. 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.
A large number of root rots are caused by members of the water mould genus Phytophthora. Perhaps the most aggressive is Phytophthora cinnamomi. Spores from root rot 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.
A plant with root rot will not normally survive, but it can often be propagated so it won't be lost completely. Plants with root rot should be removed and destroyed.
- Shurtleff, Malcolm C. (1962) How to Control Plant Diseases in Home and Garden Iowa State University Press, Ames, Iowa, p. 73;
- Yepsen, Roger B. Jr. (1976) Organic plant protection: a comprehensive reference on controlling insects and diseases in the garden, orchard and yard without using chemicals Rodale Press, Emmaus, PA, pp. 194, 208, 212-213, 226, 247, 260, 295, 321, 333, 337, 469, 488, 577, and 629, ISBN 0-87857-110-8 ;
- Ellis, Barbara W. and Bradley, Fern Marshall (eds.) (1992) The Organic gardener's handbook of natural insect and disease control: a complete problem-solving guide to keeping your garden & yard healthy without chemicals Rodale Press, Emmaus, PA, p. 401, ISBN 0-87596-124-X ;