Staghorn ferns (Platycerium spp.) are epiphytic, meaning they do not root in soil. Instead, they grow on tree bark. Home gardeners who cultivate the plants often place a layer of moss between the bark and the fern to help provide moisture. These giant, showy ferns can fascinate children, getting them interested in plants. Be ready to explain how staghorn ferns grow on trees and to let the kids touch the "horns."
Moss & Mounting
Staghorn ferns are often mounted on large pieces of bark or cork board, which are then attached to the wall of the house, indoors or out. The root balls are attached with string or wire, and then peat moss is packed around the crown of the plant. Also called sphagnum, this brown, squishy moss is very good at retaining water, which is important for a staghorn fern. For staghorn ferns grown in pots, use planting medium designed for ferns, which usually contains large amounts of sphagnum moss.
Staghorn ferns are hardy outdoors in U.S. Department of Agriculture plant hardiness zones 9 through 11 and grow best in part shade. Indoors, they thrive in bright but indirect sunlight. Filtered light, such as that through window blinds, is ideal. They enjoy mild daytime temperatures in the 70s Fahrenheit, with a drop of about 20 degrees during the night. Warm, humid conditions are best.
Once the fern is mounted, water the crowns and roots when they have dried to the touch, but try not to let the root ball dry out completely. The moss will help with this. Use a spray bottle. If the roots do dry out, submerge the entire root ball in water for several minutes. The University of Florida IFAS Extension recommends watering about once a week when the weather is hot and dry. Add a balanced (10-10-10, 20-20-20), water-soluble pre-mix fertilizer to the water once a month when you water the plant, following the package's instructions.
The species most commonly grown as a houseplant is Platycerium bifurcatum, also known as staghorn or elkhorn fern, as are most of the ferns in the Platycerium genus. This fern reaches maximum heights and widths of 3 feet, which is why it is usually mounted rather than grown in a pot. It is hardy in USDA zones 9 through 12.