Ferns, although there aren't many varieties of them available for indoors, are probably more universally used as house plants than any other class of plants. Fortunately, they're easy to grow, as well.
First, ferns need a porous soil. For example, two parts screened leaf-mould, one part sand and one part old manure or rich loam. Secondly, they should be given a warmer temperature, a minimum of fifty-five degrees at night is best, although not absolutely needed.
The third requirement for success with ferns, is a moist atmosphere, as well as plenty of water at the roots. If the pots are carefully drained as they should be, and the soil properly porous, it will be almost impossible to over-water at the roots.
They should always be given as much light as possible, without direct sunlight, and as much air as possible while maintaining the proper temperature.
Many of the ferns can be increased either by runners or division, and they can be easily propagated at home. Those that are grown from spores (the fern's seeds)...it would be better to get them from the nursery.
Most of the ferns belong to one of three groups:
The distinguishing feature of the Sword Ferns is their long pointed fronds; the Maidenhairs command attention by their beautiful feathery foliage; and the Spider Ferns, seen usually in mixed varieties in dishes or fern pans, are attractive for their shades of green, gray, white and silver, and compact growth.
The widely popular sword fern was Nephrolepis exaltata, but the original form has been almost entirely replaced by new varieties developed from it, the most widely known of which is the Boston fern. The wide popularity of this fern is due to both its beauty and its hardiness. It stands more ill usage than any other house fern and it grows quick and makes a handsome plant at all stages of development.
A well grown large Boston fern requires a good deal of room, and the long fronds (three feet or more in length) are apt to get damaged at the ends. For these reasons the Scottii fern, a development of the Boston Fern, is for some purposes a better plant. Its fronds are like the Boston Fern's, but shorter and narrower, and the habit of the plant is much more dense and compact. Of the fern house plants, it makes a perfect choice.
Another fern developed from the Boston is Whitmani, in which the fronds aren't so long but the foliage is so finely divided that it gives a plumey effect. Piersoni and Elegantissima are exceptionally beautiful, but must be given careful attention. Scholzeli, sometimes called the Crested Scott fern, is very beautiful and well worth trying.
Croweanum is a beautiful adiantum, and as its fronds are much firmer than those of most of this class, it withstands the trying conditions of the home very well. Another maidenhair, often called the hardy Farleyense, is Adiantum c. v. imbricatum. As its name suggests, it looks very much like the Farley fern, but it is suitable for indoor gardening. It's a very satisfactory fern.
They are commonly used in made up dishes, or with other plants, but most of them will make fine single plants as well. P. Wilsoni is a popular type making a compact plant with a unique tufted foliage of light clear green. P. cretica is dark green, or green lined with white, according to the variety. Victoriae is perhaps the best of the several variegated Pteris'.
The Holly fern (Cyrtomium falcatum) is another very desirable house plant and has been a favorite for years. It has very dark green substantial glossy foliage, and stands up well. Another one is C. Rochfordianum; its foliage isn't only a richer deeper green, but the pinnae, or leaflets, are deeply cut and also wavy, and have given it the popular name of the Crested Holly fern.
Asparagus plumosus nanus, the Lace fern. No foliage is more beautiful than the feathery light green sprays of this asparagus. Notwithstanding its delicacy, it keeps wonderfully well when cut. The plants can be grown as pot plants, or as vines. If wanted for a potted plant, keep the sprays pinched back at twelve inches, and the roots rather restricted. For vines, keep in large pots or boxes (always well drained) and keep well fed.
Asparagus Sprengeri in both foliage and habit is very distinct from A. plumosus. The leaves resemble small glossy pine needles, borne in long sprays, and as it is trailing in habit it makes a unique and beautiful plant for stands or baskets. The sprays keep well when cut, and make an excellent background for flowers. It is now used more universally for green by florists than any other plant.