Orchids plants are the loveliest among all the flowering plant in the world. The exquisite beauty of flowers, brilliance of colors, remarkable range of sizes, manifold shapes, variation in the form, attractive habits and wide distribution in the earth have aroused highest admiration for these charming plants throughout the world. These extraordinary plants belong to the very large and diverse family Orchidiaceae. The orchids plants with the 35,000 species and over 800 genera constitute probably the largest family among the flowering plants, and exhibit an almost inequitable umber of hybrids and varieties. They are the only major cut flower crop commercially grown as a pot plant in most parts of the world. In some of the tropical areas of the world, however, Arachnid, Aranda and Vanda orchid are grown in ground beds cut flowers.

Orchids Plants: Climate and Growing Media

Orchids plants grow in a wide variety of climate and environmental conditions and cannot be expected to conform to any one set of rules in cultivation. But the basic requirements of most of the orchid are rather similar.

Orchids Plants: Temperature

The optimum temperature varies between 15.5 to 26.5 °C for most of the cultivated orchid. For growing purposes, they are usually divided into three temperature groups: warm, intermediate and cool orchids. Warm orchids like Vanda, Rhynchostylis, Phalaenopsis and Dendrobium require moderate to high humidity. Temperature around 15.5 and 26.5 degree centigrade at night and day, respectively, are duitabel for the growth of this orchids. Cattlelya, Laelia, Brassavola and allied genera, and Oncidium, Epidendrum, Miltonia, few species of Odontoglossum mottled leaf Stanhopea, and few others are represented in intermediate orchids. For these orchids the idea minimum temperature is 13°C at night and 18 degree centigrade and above during daytime. Cool orchids include a number of beautiful genera like Cymbidum, plain leaf Paphiopedilum which do well between 10 to 13 °C.

Cymbidiums prefer cold temperature and do not flower warm areas. Night temperature between 10 to 13 °C is congenial for initiation of flowering. In case of Vanda orchids day temperature of 21 degree centigrade or above and night temperature between 15.5 to 21°C are favorable. Tropical species of Eria generally require higher winter temperature (18 to 20 °C); and high altitude species can withstand 13°C. The species of Microstylis, which possess pseudo bulbs are usually deciduous and while in cultivation require a winter night temperature of 15.5 °C and moderate rest period.

Orchids Plants: Light

Orchids require less light intensity compared to common garden plants as they are cultivated in shade or green houses. As per the available literature, some of the popular orchids used in the cut-flower industry, like Arachnis and its hybrids, Cattleya, Dendrobnium, Oncidium, and Vanda require 2400 to 3600 foot candles of light intensity. Phalaenopsis shows satisfactory growth and flowering at 1500 foot –candle light intensity, while optimum requirement of light of Paphiopedilum varies between 1800 to 2400 foot-candles. Paphopedilums do best in low light intensity, during winter; they require about 800 to 1200 foot candles and in spring though summer about 700 to 800 foot candles. Paphiopedilums flower at a low light intensity of 750 foot.

Orchids plants: Humidity

High relative humidity is generally preferred by most of the orchids. They thrive well when the atmospheric moisture is not less than 30% at night and more than 80% during the day time. Generally monpodial types, e.g. Vanda, phalaenopsis etc. require high humidity (70-75%) than sympodial types e.g. Cattleya, Laelia or those with leathery leaves (40-55%). High relative humidity reduces loss of moisture from the growing media and minimizes the frequency of watering, Relative humidity between 75 to 80% during the day. With increase in temperature, the humidity in the green house should be increased.

Orchids Plants: Container and potting media

The orchids found in nature grow wild on trees, rocks, meadows or mashes and are generally divided into three groups, terrestrials, epiphytes and saprophytes. According to the diversified habit of growth, the vegetative structure of the orchid is modified. Terrestrial orchid are generally planted in ordinary clay or plastic pots. Epiphytic orchid are best grown in specially designed orchids pots with holes at the bottom and slits or perforations on the sides. Monopodial epiphytes like Aerdes, phalaenopsis, Vanda orchids etc., are particularly suited to basket culture because of the large aerial roots produced from these plants and straight growing habit. Wooden or galvanized wire baskets are normally used. Many orchids are conveniently grown on wooden logs.

The material used as media for orchid is entirely different from that used for other plants. Hence, finding out suitable potting media for a vast range of orchid is a fascinating subject of study. Different types of materials are used as potting media for epiphytic and terrestrial orchid. Epiphytic orchid can be grown in any one or in combinations of different material like chopped Osmunda fibber, over burnt brick pieces, chunks of hard wood charcoal, coconut husk, fir bark, red wood fiber, coarse peat moss, perlite, palco wool, Hawaiian tree fern (Hapu), coke, solite, broken pieces of oil palm nuts, gravel, red lava rock, Styrofoam consisting of strips of various sizes (orchid chips), styromull (plastic foam material) etc. while terrestrial orchid grow in mixtures of several material like sphagnum moss, tree fern fibber, fir bark, pine bark, dried and un-decomposed oak leaves, beach leaves, perlite, charcoal, shell grit, milled peanut hulls , loamy soil, mould, river sand, etc.

Different potting media are largely chosen depending upon the locally available materials. In general the media should consist of materials of uniform texture through which water will brain out readily, keep the media moist but will never become too wet or soggy. An ideal medium should preferably be inert, resistant to organic decomposition, as well as porous to ensure adequate aeration for root respiration; less costly and easily available.