Just like outdoor plants, indoor plants are susceptible to diseases. Insects, fungi and bacteria can invade the roots, soil and leaves of houseplants. When plants are exposed to high humidity, improper ventilation or overwatering, they are prone to disease.
Powdery mildew occurs in houseplants when the air around them is humid and there is poor ventilation. If the disease is caught early, the plant can be saved. Remove dead parts of the plant, then move it to a location with less humidity and better ventilation. Plants that are susceptible to this disease include African violets, begonias and roses.
Wilts is a disease that interferes with a plant's root system. Fungi and bacteria will develop in the soil and then enter the plant through the roots. Symptoms of this disease include leaves that wilt or turn pale. After not receiving the desired amount of water, the leaves eventually turn brown. To fight the disease, cut off the infected parts of the plant or replant it in a disinfected pot.
Root rot occurs when a plant is overwatered and micro-organisms begin to develop in the moist conditions. The stems will droop and appear as if they need water, then the roots turn mushy or brown. The plant may actually fall over. If you catch this disease early enough, you can repot the plant in new soil and move it to a drier environment. Common houseplants susceptible to this disease include cacti and succulents.
Gray Mold or Botrytis Blight
Botrytis blight occurs when a plant has become overcrowded or must endure high humidity. It also occurs when dead parts of the plant have not been removed. Signs of the blight include fuzzy gray growth on the plant. To cure a plant of this disease, remove the leaves or flowers that have mold. Water the plant less and keep it in a drier environment.
Nematodes are tiny pests that attack plants by burrowing into the tissues of the roots or foliage. Signs of nematodes include a lack of growth or wilting. The leaves begin to lose their color because of the lack of necessary minerals. If it is a flowering plant, the plant may also no longer bloom. To fight these pests, the plant may require repotting in new soil. Before repotting, double-check the roots for signs of nematodes.