There are several reasons whyhave not yet caught on as house plants. They are a genus of great variety and, no doubt, will one day become extremely popular as indoor plants. Meanwhile many people are rather afraid of growing them, because they think that need extremely high temperatures, are costly plants and are rather precious and delicate. In reality a great many orchids do not need higher temperatures than many other house plants. At temperatures above 4°C throughout the year, many of the cultivated orchids would grow easily out of doors. That they are relatively expensive is quite true, but orchids are not as expensive as they were formerly, and will no doubt get less expensive as culture increases.
Most orchids are epiphytes, dependent on organic matter washed down by rain from surrounding vegetation for nourishment. The plants attach themselves to trees by their This may be leafless or put forth several thick leathery, or light thin, . From the base, or the axils of the leaves, the flowering stem grows out. After flowering the pseudo-bulb puts out shoots from its base which develop like itself, and in this way the plant multiplies. In some species flowering only takes place on a new bulb, and in others the older ones may bloom for several years. The epiphytes may be grown on a piece of bark, wood, or fibre, to which the plant is strapped or wired, with a pad of Sphagnum moss or Osmunda fibre to cover the roots. In due time the roots attach themselves and the binding can be removed. They should not be over watered and the slabs can be hung by a hook in a sunny window, but not in direct sun., and most of them have a pseudo-bulb which stores water and nutriment during the dry season.
Terrestrial orchids grow with roots in the ground like other plants and may, or may not, have a pseudo-bulb above ground level. Theare more attractive than those of the epiphytes and they are grown in in fibrous soils. The Cypripedium hybrid, Ladys Slipper, is an ideal terrestrial for the amateur. It is getting cheaper and should soon be within the reach of all pockets. The waxy flower, in shades of brown, yellow, white and pale green, with a mass of speckles, has a protruding lower slipper-petal which is highly polished. It in winter and lasts,
either on the plant or as a cut flower, for several weeks. It may needafter flowering but, if the assistance of an grower is
available, his help should be sought as repotting orchids is a tricky business for a novice. If the plant is not cramped it can stay put for two to three years.
Baskets, preferably of teak, are good containers for these orchids and should be in partial shade; a pot can also be placed on a tray, or saucer, of moist pebbles and left in a north-west window. Cypripediums must be protected against hot sun, have fresh air in moderation, never be allowed in draughts and have a winter temperature of around 16 to 17°C. The plant can be watered lightly until it has settled down and, when growing freely, it can be sprayed and watered freely as it appreciates. A uniform moisture should be kept throughout the pot, the soil being allowed to dry out between waterings. The foliage should be kept clean by sponging.
Cymbidium hybrids are also terrestrial orchids that do well in cool conditions and are not demanding over the matter of light. They produce their flowers on erect or branching spikes, which vary in height from 1 to 4 feet, according to species or hybrid. Some of the Dendrobium species can also be grown as house plants, although they need a little more heat than cymbidiums. Dendrobium nobile is a winter blooming orchid, which does not require a very high temperature and can do well in ordinary window light. Orchids are very economical to keep for they live on less than most plants and their rate of growth is very gradual. A high-nitrogen fertilizer should be used once a week, diluted to a quarter of the recommended strength, and every three months they should be watered for two weeks with an organic fertilizer. Most orchid pests can be killed by dipping the plant in mild malathion solutions.