- There are well over 100,000 different hybrid orchid varieties in existence.maroon orchid,orchid,maroon,showy,flower,beautiful image by Earl Robbins from Fotolia.com
The orchid family of flowers encompasses approximately 25,000 different species, making it the second largest family of flowering plants. In the 1700s, orchids were transported from China and the West Indies to England, where they gradually became a status symbol and obsession among the 19th-century British elite. Along with the mass transplantation of orchid flowers from their native habitat came a number of diseases, most precipitated by improper growing conditions.
- Basal rot is a disease brought about by improper watering of the orchid. Specifically, basal rot is caused by over-watering the orchid, or by leaving any excess, standing water in the soil around the base of the flower stem. The rot starts at the bottom of the flower and works its way up the stem. An orchid plant with one diseased growth among many otherwise healthy growths can usually be saved by simply excising the dying growth and applying sulfur to the cut area.
- Botrytis appears as an outbreak of small black spots on the petals of the orchid. These spots are a fungus and will increase in size to become gray patches of mold if the disease is left untreated. Botrytis is a result of orchid growth occurring in a cool, damp environment with stagnant air.
In the event of botrytis in one or more of your orchids, remove the afflicted orchid plants from the soil for disposal and spray all other surrounding orchids with a mild liquid fungicide to prevent the further spread of the fungus.
- Pseudomonas cattleyae is a form of rot that spreads quickly, wiping out orchid plants within a couple of days. It is characterized by the formation of soft, dark brown moist spots on orchid leaves and is caused by excess humidity, cool temperatures and stagnant air.
In the early stages of the disease, the leaves can simply be removed with a sterilized cutting tool and the cut area dusted with sulfur. Once pseudomonas cattleyae has reached the crown of an orchid, the plant is beyond saving and should be removed to prevent infection of surrounding plants.
- The most difficult orchid disease to identify and combat is the orchid virus, which does not make itself visually known until the disease is already too advanced to halt and reverse. The virus is spread by insects and unsterilized cutting tools.
When orchid virus does become visible, it is characterized by black rings or spots that are either circular or diamond-shaped. There is no cure for orchid virus, and unlike other orchid diseases, the virus will infect all types and genuses of orchid plant.