About one hundred species of orchids belong to the genus coelogyne, originating in central and southern Asia; c. cristata is a species of Nepalese and Chinese origin, widespread at quite high altitudes, in cool climates. It produces fleshy pseudobulbs, oval-shaped, quite large, from each of which sprout two long, ribbon-like, leathery, bright green leaves; already during the winter, at the base of the pseudobulbs, the stem is produced that will bring the flowers, which will bloom in spring, gathered in an arched inflorescence, 15-20 cm long. The flowers are large, very showy, of a pure white color, characterized by petals and arched sepals, and by a trilobate labellum, which has some golden-yellow streaks. The coelogyne flowers are very showy, and a single plant can also produce some floral stems, which each carry 3-6 flowers. The flowers of the other species of coelogyne are always large, some even perfumed, and the colors are quite muted, from white to beige, from yellow to light green.
These orchids should be placed in a very bright place, possibly away from direct sunlight, although we can expose these plants to sunlight for a few hours a day, during the coolest periods of the year and early in the morning. To obtain a good flowering it is advisable to cultivate the plants in place with a fairly warm climate, from March to September, while during the cold months it is good to place them in an unheated room, or even in a cold greenhouse, with minimum temperatures close to 7-10 ° C.
The environmental humidity for this type of plants must be high, even to eighty percent in the hottest periods.
From April to September, let's water abundantly, keeping the soil always slightly damp; in the same period we will take care to vaporize the leaves, to increase the environmental humidity and to lower the temperature during the hottest days. During the cold months we can thin out the waterings, intervening only if the pseudobulbs tend to lose turgidity.
It is also good to have a correct fertilizer, using a fertilizer with a good phosphorus component in spring and autumn to increase flowering.
The roots of the Coelogyne are quite thin and delicate, so it is advisable to use a fairly fine soil, consisting of small pieces of chopped bark, perlite granules and bits of vegetable fiber or peat. It is advisable to avoid too frequent repotting in order to avoid ruining the root system which is very delicate. Intervene when you notice that the roots are forced inside the vase.
The multiplication of these orchids takes place by division of the tufts, although often the division brings the plants to a lasting decay, so it is to be practiced with all the necessary precautions, using clean and disinfected tools.
The Coelogyne also multiply by seed, taking into account the fact that new plants may not have the same characteristics as the mother plant.
Coelogyne: Parasites and Diseases
These orchids fear the attack of aphids and cochineal. To eliminate the latter, if they are not massively present, it is possible to intervene manually, using a cloth soaked in alcohol to pass over the leaves. There are also special insecticide products that guarantee good results to eliminate the problem.