Coelogyne comprises nearly 200 species which are distributed from India, through south-east Asia, down through Indonesia into New Guinea.
Here in Tasmania we grow many of the cooler varieties that come from the foothills of the Himalayas and at high elevations through Vietnam with great success. They need morning sunshine so protect from hot afternoon sun in Summer.
The most commonly grown species are corymbosa, cristata, flaccida, fulginosa, massangeana, mooreana, nitida, ochracea and ovalis. As they grow within the Tropics but are at high elevations, they have warm, wet summers and cool dryish winters. Average temperatures are 25C midday, mid-summer down to 8C midnight, mid-winter.
There are many and varied growing media for Coelogynes depending on their individual growth habits. You can pot them in a pine bark mix or in just sphagnum moss. Alternately you can grow many of them on a piece of cork bark or manfern slabs. Just remember that when it comes to watering, you will need to be more generous when growing on a mount compared to growing in sphagnum moss. Keep plants on the dryer side of moist during winter. Humidity should be high all year round as they do grow in mountainous regions, not flat deserts.
Fertilize weekly with a quarter strength balanced fertilizer during periods of active plant growth. The plant will tell you when that is as there will be new growths showing themselves and active root movement into the potting mix or along the bark.
Don’t be worried if your Coelogyne cristata buds appear to be browning off as they stretch out along their stems. You will see the transformation from ugly duckling into beautiful swan as they discard their protective husks and unfurl themselves into clear white wonders with yellow centres. (Unless you have the alba form and they will be just white)
Be aware that many of the Coelogyne species are highly perfumed, so if you have an allergic reaction to them, it is best that they be left outside when in bloom instead of bringing them into your home to enjoy. They will though, last a lot longer in flower if kept cool and humid, not warm and dry.