Growing Orchids

The secret of successful cultivation of orchid is to provide them with conditions as identical as possible with the environment under which they were growing in the wild . Due to their peculiar nutrional habits , orchids require special techiniques of cultivation , if they are to grow healthy and put out a good crop of flowers . Towards this end the following factors should be provided in their optimum : light , water , humidity , temperature and a suitable medium in which the orchids are to grow.

The optimum in each of these factors varies from species to species and since these factors are to be controlled , orchids are generally grown in special orchid houses ,which are of two types - Open houses and closed one . The open type of house is mainly employed in tropical countries where humidity and temperature are at their most favourable . This sort of house provides some amount of overhead protection from the blazing noon day sun of the tropics , which might cause leaf burn in the more delicate of the species . Warm growing species which require only a small amount of shade above and moist surroundings , do very well in these green houses . A brick-paved floor will help to retain moisture and coolness. The roof is most commonly made of split bamboo stems or teak scantlings speced out in such a way as to allow filtered sunlight to pass through . The bamboo or wooden scantlings are positioned north- south so that direct sunlight will not fallen on the leaves except for short periods . The scantlings could be supported either by simple teakwood poles or by a more permanent wooden framework . But this type of orchid house possesses a serious disadvantage . Since the roof is not waterproof , the orchids are likely to get water logged during the heavy rainy season , resulting in damage to plants.

The closed houses are meant for orchids which should be grown under controlled condition s of temperature and humidity . They are completely covered on all sides with glass or any of the substitute materials which are available these days , like polyethylene sheets or panels . Glasshouses should have permanent foundation, a strong framework and a roof. It may have a brick wall upto half the height of the house , which is best avoided in warm countries . The whole structure is supported by wooden , aluminium or galvanised iron poles resting on concrete foundations. Aluminium is, of course, much more expensive than wood. The floor should never be of concrete, since it is incapable of retaining any amount of moisture. Paved brick or a thick layer of gravel is the best for flooring . The space inside the glasshouse should be so arranged that maximum space is made available for the plant . The pots should be arranged on benches for purposes of aeration . Wooden benches in three or four tiers lining the four purposes of aeration . Wooden benches in three or four walls of the glasshouse and a centrally situated aisle , where again tiers of benches are arranged , would be the most suitable arrangement . A pathway should be left between the central aisle and the benches on the sides. Wooden benches made of scantlings fixed an inch or two apart are preferred to concrete benches , since the former retain moisture and allow plenty of air to circulate among the pots . They are also cheaper . Heavy wire meshes are also sometimes used in place of wooden scantlings . Beams should be fitted under the roof for hanging epiphytic species which require more of sunlight and also those which are of the pendant type .

During summerime , the panels on top get a coating of lime in order to cut off excess sunlight . This is washedoff as winter sets in . Removable shadings like that of saran fabric are also sometimes fitted for the same purpose . Ground glass which allows only diffuse sunlight to pass through is much more desirable than ordinary plain glass , but the cost is high . In recent years desirable property of allowing only diffuse sunlight to pass through them, which makes additional shading unnecessary during summer .