Coelogyne speciosa
Coelogyne Coelogyne grows on trees and sometimes rocks in cold high altitudes (up to 2500m) of the northeast of India, Tibet, Nepal and into China where they may experience wet summers and cold winters.
Light & Air Coelogyne should be grown in full shade with 85% humidity in summer and early autumn, decreasing to 60-70% in early winter.
Temperature Coelogyne needs a large drop in temperature between summer and winter but this could be from 80°F to 59°F and watering should be reduced as with all plants over winter to prevent the roots rotting in dank badly drained soil/media.
Water & Fertilizer The plant should be watered heavily while actively growing, with little if any drying allowed between waterings. Water should then be gradually reduced after new growths have matured in autumn and limited in winter to occasional light waterings or early morning mistings. More water should be given if the tips of the youngest leaves start to die back or if the pseudobulbs show signs of excessive shriveling. The leaves on the older pseudobulbs may naturally die back during this time, but the tips of those on the newest growths should remain green. Likewise, slight shriveling should occur on the newest pseudobulbs. No shriveling at all indicates the plant may not bloom because of too much water. Water should be gradually increased in spring after new roots begin to grow. A balanced fertilizer mixed at 1/4-1/2 recommended strength should be applied weekly during periods of active growth
Potting Plants may be mounted on cork or tree-fern slabs if humidity is high and plants are watered several times a day during hot, bright weather. Plants are usually grown in shallow pots or baskets using an open, fast draining medium. Fine to medium sized fir bark or tree-fern fiber is often used alone or mixed with varying amounts of additives such as charcoal, perlite or chopped sphagnum moss. Many Coelogyne do not like to be disturbed and may sulk for 2-3 years after repotting or dividing. When repotting is necessary, be sure it is done only when a flush of new root growth is just starting. This will allow the plant to become re-established as rapidly as possible.
Other Tips Leaf-tip die-back may be a problem with many Coelogyne species. While normally not fatal, it does cause unsightly plants and is usually an indication of a cultural problem instead of disease. Underwatering may cause these symptoms as may excessively low humidity. In most instances, however, the culprit is probably an excess of salt buildup in the medium which may be remedied by flushing the medium as previously discussed. These same symptoms may also be caused by root rot resulting from too much water, usually with old, broken-down medium.