In South Florida staghorn ferns will form great masses high in the trees.
The 18 species of Platycerium are epiphytic ferns, growing naturally on the rough bark of tree branches. Usually called staghorn or elkhorn ferns, they are characterized by large, flattened bifurcate or trifurcate fronds that seem to erupt from their bases in all directions. Staghorn ferns have two distinct kinds of fronds: Large antler shaped green fronds which are forked and spreading, upright or pendulous; and rounded or kidney shaped (usually brown) fronds which are overlapped like scales, and form a "nest" around the base of the plant. The large green fronds are fertile (they produce spores for reproduction), and the padlike brown fronds are sterile. The spores appear as brown patches on the fertile fronds. Small offset plants or "pups" develop among the basal fronds of most species. P. bifurcatum is the most commonly cultivated staghorn fern, the hardiest, and probably the easiest to grow. It produces grayish green spreading and pendulous antlerlike fronds to 3' long, and rounded clasping sterile fronds to a foot across. P. grande is larger with upright fan shaped sterile fronds forming a nest to 4' across, and hanging strap shaped fertile fronds to 6' long. P. hillii is smaller with fronds just 2-3' long.
The staghorn ferns grow high up on trees in tropical and subtropical rainforests, mostly in Australasia and Africa with a single species in South America. P. bifurcatum hails from southern Australia.
The roots of staghorn ferns are for attachment only. They get their water and nutrients from the air. The fronds of staghorn ferns are covered with tiny grayish scales that may look like dust; these serve to limit evaporation - do not rub them off. Light: Staghorn ferns do best in bright light, but not direct sun. If only artificial light is available, they should have at least 400 foot-candles. Staghorns thrive suspended in the filtered light beneath a canopy of trees. Moisture: The entire staghorn fern and the organic material to which it is attached should be dunked once a week in a dilute solution of fertilizer and rainwater. Staghorns thrive when the fronds are misted daily, but they can do without, even in a centrally heated room. Rainwater is best, but soft water can be used. Hardiness: USDA Zones 9 - 11. Staghorn ferns do best with daytime temperatures in the 70's and night temperatures in the 50's. P. bifurcatum can tolerate light frosts and has been known to survive temperatures as low as 24 F. Propagation: For those species of Platycerium that grow in clumps, you can start new plants from the small "pups" that grow among the fronds at the base of the plant. Nonclumping species such as P. grande can only be propagated from spores and this can be quite a difficult undertaking.
In frosty areas plant staghorns in containers or mount on sphagnum moss planks and hang in a tree. Move indoors for the winter (they like to live in the bathroom where the steam from showers keeps them fresh.
Staghorn ferns are grown on a moisture retentive medium such as tree bark, osmunda fern root or sphagnum moss, usually in hanging containers or mounted on wall planters. In frost free climates they can be attached to trees. Staghorn ferns are best suited to greenhouse cultivation, but can be grown in the home if water is supplied regularly. In South and Central Florida they are often grown in containers suspended beneath a large tree. Staghorn ferns can grow to enormous size, even with little care, and a large specimen is truly impressive.
Staghorn ferns are epiphytes, using trees for support only; they do not obtain nourishment or water from the host tree as would a parasite - see dodder (Cuscuta spp) for an example of true parasitic plant. Photosynthesis takes place in the green fronds just like any ordinary plant leaf. But the overlapping brown fronds near the base of the staghorn fern serve to trap falling debris such as dead insects and pieces of plant material; this is where the fern gets its minerals and other nutrients that most plants would get through their roots from the soil.