It takes a little effort to grow a fine specimen of any type of plant, and ferns are especially responsive to that extra effort. As was mentioned last week, it is important to know something about the ferns themselves and their care in advance of making a purchase. Besides a knowledge of the fine points of care, your interest in ferns will lead you to additional considerations.
To begin with, in selecting a fern you will probably be thinking of where you are going to place it or how you intend to display it. The type of growth will influence your choice - that is, whether it will become a monster like Staghorn, a fountain like Boston, or a miniature and modest like Button Fern or Victoria Fern.
Confusion in selection may arise when you haven't learned in advance the difference between plants with similar names - for instance, Southern Maidenhair and Rosy Maidenhair, both Adiantum species, or between Japanese Holly-fern (Cyrtomium) and East Indian Holly-fern (Arachniodes), two different species.
Part of the fascination of ferns is in their differing methods of reproduction. In addition to reproducing themselves by spores (rather then by seeds), they multiply by vegetative budding and by division. Your selection may be based on your wish to observe these differences or merely to include in your collection examples of several types of propagation.
As a rule spores are borne on the undersides of fronds. In many instances the spore-bearing, fertile frond is modified in some special way or the fertile frond does not look very much like the sterile frond, so that you might think there are two different ferns in the same pot.
A totally different example of reproduction (vegetative budding) is observed on the Mother Fern (Asplenium viviparum), which produces tiny ferns on mature fronds; they can be removed and grown under humid conditions to increase the number of plants. In nature, they drop to the ground and thus spread their species.
General suggestions for care of ferns were given in last week's column. The following are some notes on ferns that are most popular with indoor gardeners.
Maidenhair - Adiantum
Keep it cool. Water it often. Mist lightly. If it dries out at some point in its cycle, it will turn brown. Cut off brown fronds at the crown. Shear it once or twice a year to bring up fresh fronds. Divide it often with a sharp knife or hatchet.
The Southern Maidenhair, Adiantum Capillus-veneris, is generaly hardy outdoors in this area. RosyMaidenhair, A. hispidulum, is rose-colored when young changing to medium green. The leaf structure differs slightly from Southern.
Bird's Nest - Asplenium nidus
Because of its vase shape or its nested straplike fronds, your friends may not believe that this is a fern, but you know better; you've chosen this fern for its distinctive bold character. Keep it constantly moist. Misting will increasing surrounding humidity. Keep it in a warm room out of direct sunlight. It is difficult to divide.
Japanese Holly-fern - Cyrtomium falcatum
Well known for the holly-like appearance of the fronds, this tropical fern can be planted outdoors in summertime. In the house, give it a cool room, out of direct sunlight. Its leathery fronds will tolerate heat and dry atmosphere better than most ferns.
Boston Fern - Nephrolepis exaltata bostoniensis and its many cultivators
The Boston Fern is a mutation from the Sword Fern (Nephrolepis exaltata) and itself has been improved in cultivation; two good cultivars (cultivated varieties) are Norwood and Whitmannii.
This fern appreciates an almost dry period between waterings. The best way to water a large Boston fern is to immerse the pot up to the rim in a pail or tub of water for an hour once or twice a week - depending on the dryness of the home atmosphere. It can be set outdoors in gentle rain when the temperature is above 50 degrees - both cleansing and refreshing. Misting is also acceptable except that the highly "ruffled" forms should be only lightly misted because the droplets of water are likely to be held too long in the involved leafage.
The Boston fern constantly drops leaflets and becomes trashy. Occasionally a frond will be produced that is a reversion to the original unruffled Sword Fern from which Boston Fern is derived. When this occurs, cut off the sword frond.
If it is too warm or dry, the fronds get brown. It likes to be potbound, but if it outgrows its pot (the whole plant rising up in the pot)), it can be divided by cutting it into pieces of desired size with a sharp knife. It will endure a wide range of light, from partial sunlight to light shade. Rabbit's Foot Fern - Davallia griffithianum
The davallia ferns are epiphytic. They are characterized by the furry rhizomes (modified stems) exposed and creeping over the surface of the growing medium. Hare's foot and squirrel foot are other common names.
Rabbit's foot is most often grown in a hanging basket or log-cabin box; it can also be planted in a pot. It needs high humidity and plenty of moisture. Give it indirect or filtered sunlight.
The "feet" will crawl out and root on the surface of the medium in an adjoining pot. Fasten them down to the medium with wire bent like a hairpin until roots form; when fronds are produced, separate the newly formed plant from the original by cutting the rhizome.
Staghorn Fern - Platycerium bifurcatum
This is a tough epiphytic fern, but attention must be given to its moisture and high humidity requirments; mist is often. Grow it on a cork bark plaque or in a log-cabin box in medium light. Every five or seven days immerse the plaque or box in water so that the growing medium is kept constantly moist; it is difficult to remoisten a fibrous epiphytic medium that has dried out. Staghorns frequently suffer from over-watering when grown in pots.
Give the Staghorn filtered sunlight in the winter and outdoor shade in the summer.
It is best to start with a small plant as large plants suffer greater shock when removed from the greenhouse.
Button Fern - Pellaea rotundifolia
This is another species that has scant resemblance to other ferns; as the name rotundifolia indicates, it bears little round leaflets. The rhizome grows rapidly, and a large pot is needed to accommodate it. Keep it in open shade in the summer and filtered sunlight in the winter. It may grow faster than you would wish if you plant it in a terrarium.
Pteris species, varieties or cultivars
These are the table ferns (or brakes). Several have variegation consisting of white centers or white margins on the leaflets. They are suitable for terrariums and dish gardens, or for planting at the base of other plants. The difference between the fertile and sterile fronds is conspicuous in some species.
Climbing Fern - Lygodium japonicum (or Lscandens)
Provide a trellis for this delicate fern, allowing filtered sunlight. It will climb three or four feet; top pruning will restrain it. Fish emulsion is a good fertilizer, alternating occasionally with an acid-type houseplant foot. When the fern becomes shabby, cut it back to the pot and allow new growth to develop. It may be started in a hanging basket, but once established it will soon start to climb. It can be allowed to climb on other plants as well.