Indoor ferns require a situation that replicates to some degree their natural growing environment. They can thrive in a lot less light than most plants but can be temperature sensitive.
Many plants in the foliage classification are, technically,, although their may have little ornamental value. Even Aspidistra, a foliage plant if ever there was one, has purple-maroon flowers an inch across, yet many people grow it for years, never seeing the flowers, so shyly are they displayed. Ferns are, however, definitely flowerless plants making up for this by the elegance and beauty of their fronds. Many ferns naturally inhabit shaded `places and are able to thrive in a subdued light, which makes them particularly useful in dimly lighted locations in the house.
Adiantum pedatum is the popular and beautiful. The finely divided are from 4 to 16 inches wide and almost horseshoe-shaped. The stalk is wiry and a shiny black. Adiantum grows easily does not need much heat but does need , in common with most ferns. Propagation is by division ir1 the spring.
Asparagus plumosus is so well-known as thethat it is included here. It is, however, not a fern at all but a berry-bearing evergreen climber. The are various colours of green, feathery, and may be trained up wires or strings. It welcomes good light, free and syringing in the summer, very moderate watering in winter = and a minimum winter temperature of 10° to 13°C. Asparagus sprengeri is an emerald green climber, good for hanging baskets, with needle-like leaves and small white flowers on the adult plant followed by red berries. A lover, this plant should be sprayed frequently and given plenty of water when growing. It is best grown in partial shade and should be kept out of the sun, which might discolour the foliage. A winter temperature of 12°C should be maintained. All Asparagus need for most of the year and plants should have monthly doses of a liquid manure when fully established.
Asplenium nidis (Birds Nest Fern) is striking for its bright green undivided fronds, springing 2 to 4 feet in length and which make a nest formation at the crown. It has a variety, australiasicum, in which the midribs of the leaves are black. This plant requires moist, heated, conditions, a minimum winter temperature of 15°C and shade. It should be watered liberally in summer, more moderately in winter.
Nephralepis exaltata (Boston Fern) is one of the tropical ferns that can be used in the house. It has finely cut, pinnate fronds of up to 2 feet long, 6 inches broad, growing rapidly and, therefore, requiring a fair amount of space. There are several more beautiful species such as N. magnifica and N. whitmanii, in which the fronds are more finely cut. N. cordifolia compacta is another useful plant of a deep glossy green colour, with arching fronds, again about 2 feet long. These ferns like a summer temperature of about 21°C, with shade and liberal watering and winter temperature of a minimum of 10°C and more moderate watering.
Phoenix dactylfera (Phoenix Palm) is the Date Palm of North Africa and Arabia and is an attractive pot plant with grey green leafleted leaves that arch gracefully. It will grow well indoors for a number of years. The plant needs copious watering throughout the summer, with frequent sponging of the foliage if it is kept in warm rooms. Only moderate water- ing and a minimum temperature of 13°C is necessary to maintain it in winter.
Phyllitis scolopendrium (Harts Tongue Fern) is hardy and makes a decorative pot plant for cool or unheated rooms. The bright green strap-like leaves are 6 to 12 inches long and especially attractive are the more sophisticated varieties such as crispum, which has frilled edges, and cristatum with its crested fronds. The species are very variable, so it is as well to choose your plants at the nurseries. Virtually ever-green, these plants like shady quarters and regular watering in summer, rather less in winter with a minimum temperature of 7°C. Propagation is by division in spring.
Plutycerium bifurcatum, often known as P. alcicorne, is another indoor fern commonly called the Stags Horn Fern.
Pteris cretica has fronds that reach 1 foot in length and comes from tropical areas. There are numerous varieties. It should be grown in a peatyand positioned in a shady part of the room. It can be watered freely in summer moderately during the winter months and the temperature should never be allowed to fall below 10°C.