Hopefully these links will help:http://edis.ifas.ufl.edu/mg015 "Because of their relatively large size, staghorn ferns are rarely grown in pots except when produced as small specimens for sale at nurseries. Their natural, epiphytic growth habit makes them well suited for mounting on slabs of wood, tree fern fiber or wire baskets. To mount a fern on a piece of wood or tree fern fiber, place a few handfuls of organic growing medium such as peat, compost or rich potting soil on the wood slightly below center. Shape it in a circular mound and place the fern on it so that the basal fronds are in contact with the mounting material. Use wire (not copper), plastic strips or nylon hose to secure the fern tightly to its mount. When a wire basket is used, pack it with an organic medium and mount and secure the fern “face-up” on the medium. Hang the basket sideways. Pups (small plants) will eventually emerge from the back and sides of the basket and completely cover it.''
http://www.marthastewart.com/244112/staghorn-ferns-mount
Personally, I've never had much luck with staghorn ferns on plaques. I prefer to use a plastic or wire hanging basket and let the fern envelope it.
