By ROBIN ROBINSON Key West Garden Club
The fern family was the first plant family on Earth more than 360 million years ago. There are over 12,000 species of this non-flowering plant occurring all over the world. They are so primitive that they do not reproduce by germinating flowers but by producing asexual spores on the undersides of their leaves. These tiny spores are spread by the wind.
The strangest of this spore-generating plant family are the 18 species of the staghorn fern, the most common being Platycerium bifurcatum native to Australia and New Guinea. Staggies, aficionados who value their collections of staghorns, enjoy them for their unusual growth habits.
These plants are epiphytes, that is, they grow on a tree but are not parasites not drawing nutrition from their hosts. They have two distinct types of leaves. A folier frond that stands upright and falls into a long draping leaf that looks like the two pronged horns of a stag, hence its common name. Bits of debris and water fall into the area at the top of the leaf. These decay and nourish the fern. This leaf produces chlorophyll to feed the plant's growth.
The second leaf is a basal or sterile frond. It looks like a small plate about six inches in diameter. It attaches itself to a tree when pale green and slowly turns light brown as it matures. Nutrients are caught in the overlapping basil fronds.
Both kinds of fronds are covered with small star-like hairs that protect them from predators and conserve moisture.
Staghorn ferns grow around the world in temperate zones. They do not like freezing weather. They will add pups and these clones can grow the plant to weigh hundreds of pounds. New staghorn ferns can be obtained by cutting off a pup from the mother plant and mounting it on a piece of untreated wood. Eventually, the piece of wood will disappear inside the growing fern. Put some nutrients under the fern and use wire, plastic or nylon to tie the basal leaf on to the board. Make sure that the folier frond is pointed downward so a little cup is created at the top.
Some gardeners feed their fern bits of banana peel. Warning, this practice could become obsessive.
Watering a staghorn is tricky because the outside of the basal frond may be totally dry but the inside could still be wet. The fern should dry totally before re-watering. If it is watered too much it will rot and die. The older the fern, the better it tolerates drought. Experts recommend waiting to water until the fern wilts. Rhizoctonia, a black fungus that creates black spots on the leaves can occur when the fern is kept too wet. Mealy bugs and scale will attack a staghorn that is kept too wet. Do not use oil-based compounds to treat the plant.
For vigorous growth the gardener can fertilize, but be careful what you wish for. How many pounds of staghorn do you want in your tree? Dappled light suits a staghorn best.
Staghorn ferns can be seen in the Orchid Arbor of the Key West Garden Club at West Martello.
The Key West Garden Club welcomes volunteers to pull weeds, learn to propagate plants and play in the sandy soil at the West Martello Tower from 9 A.M. till noon on Mondays.
Key West Master Gardener Robin Robinson was a columnist for the Chicago Daily News and syndicated with Princeton Features. Her books "Plants of Paradise" and "Roots Rocks and Rain: Native Trees of the Florida Keys," can be found at the Garden Club and on Amazon.com. This column is part of a series developed by the Key West Garden Club. For more information visit www.keywestgardenclub.com.