Staghorn ferns (Platycerium spp.) are tropical plants that have a low susceptibility to pests and diseases; however, neglecting the particular care requirements of staghorn ferns will lead to diminished health and vigor and can leave the fern vulnerable to pest and disease attack such as snails, slugs and Rhizoctonia fungal infection.
A common problem with staghorn ferns is light deficiency. Staghorn ferns thrive in full to partial shade; it is important to remember that even in shade, plants receive sunlight. According to the University of Florida Cooperative Extension Service, staghorn ferns that receive extremely low light will grow at a slow rate and are more susceptible to attack by pests and diseases. Make sure your fern receives adequate sunlight.
The University of Florida Cooperative Extension Service asserts that the highest occurrence of problems with staghorn ferns is due to incorrect watering. Staghorn ferns are negatively affected when the soil is not allowed to dry out completely between waterings. Even though the soil may appear to be dry, deeper layers may still be completely wet. Water once or twice a week depending on the size of your plant (during warm weather); in cooler weather, decrease watering. Watering at the appearance of a slight wilt is an option often employed in commercial growth of staghorn ferns.
The fungus Rhizoctonia may infect the susceptible staghorn fern, causing black spots on the fern's fronds. If left untreated, the disease may spread to the entire plant, leading to death. Generally caused by excessive watering, the only treatment necessary may be a decrease in watering. For a more severe problem, the University of Florida Cooperative Extension Service recommends contacting a local county extension agent to determine a course of action through chemical control.
Though the variety of insect pests is low in staghorn ferns, an infestation can quickly injure your fern. Mealy bugs, slugs and snails can be problematic. Insect pests feed on staghorn ferns by devouring plant tissue or sucking the plant's juices. If left untreated, the fern may lose vigor, become more susceptible to fungal infections, or may eventually die. For control of insects, the University of Florida Cooperative Extension Service suggests applying non-oil-based insecticides, as oil-based insecticides can burn or injure staghorn ferns.