Diseases and Orchids

Orchids, despite their delicate appearance and reputation, are quite hardy plants that are resistant to diseases and pests – as long as they have the right growing conditions. Your best defense against the diseases and pests that affect orchids is to make sure that you keep humidity, light, temperature and ventilation levels within the optimal levels for the orchids you're growing.

Water problems are one of the key causes of problems that affect orchids. Standing water on the leaves or around the roots can encourage root rot and invite bacteria and fungi to attack the plant. Controlling the humidity level around your orchids can help prevent many of the most common pest infestations and diseases that damage and kill orchids.

Spider mites, mealy worms and scale are insect pests that are attracted to orchids. Many orchid enthusiasts recommend a monthly spraying with an insecticide like orthene or Malathion to discourage infestation. Carefully wiping leaves with a soft, soapy cloth will also help remove pests and bacteria that may cause orchid diseases and injury, orchid care

Bacteria and viral infections can take hold in one orchid and spread to others. If you notice black sooty fungus, brown or black spots of decay on leaves or flowers, or broken discoloration on leaves or stems of your orchids, they may be harboring a fungus, bacteria or virus. While most fungi and bacterial infections are treatable, an orchid infected with a virus can't be cured – and should be burned to prevent the spread of the virus to any other orchids in your home.

To prevent the spread of virus and bacteria, practice good plant hygiene. Sterilize any cutting blades or instruments between plants to avoid carrying disease from one plant to another.