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.