SF, Feb 2012
Partial shade, cold to cool temperature, flower in fall, fragance This small sized, lithophytic and epiphytic, cool to cold growing species is from southwestern China, India, Nepal, Vietnam, north Thailand and Myanamar where it grows in primary highland cloud forests on mossy trees and the rocks below them at altitudes of 1500 to 3400 meters with shortly cylindrical, maroon pseudobulbs covered by greenish warts carrying 2 apical, narrowly elliptic-lanceolate, acute leaves and blooms on a basal, erect, 3 to 6" [7.5 to 15 cm] long inflorescence with a single, fragrant [of primrose] flower and warty, basal sheaths that appears in the fall on old, leafless psuedobulbs.
Where to grow them?
Pleiones come from areas with distinct seasons of Spring, Summer, Autumn and Winter and grow best wherever the average summer temperatures dos not exceed 25 centigrade (though a few odd days up to 30 centigrade is tolerated). In winter, while they are dormant, they need to be kept cold but just frost-free. A range between 1 and 5 centigrade is ideal. If need be, small numbers can be kept in a fridge if your winters are usually too warm. Within these restraints they may be grown on a windowsill, in a glasshouse or coldframe and may be outside for those months that are frost-free. In areas with few and gentle frosts they can even be planted in the garden. But most people grow them as pot plants.Watering
The critical time is early in the season. The roots usually start to grow more or less as the flowers fade and at this time it is important to give only a little water - the aim is to keep the compost only-just damp and make the newly-emerging roots go searching for moisture. If the mix is too wet at this time there is a danger the new roots will rot. Once however the roots are well established (often evidenced by rapid leaf growth) watering can be increased substantially. Pleiones come from areas which get the summer monsoon. As long as your mix is very free draining, it is difficult to give them too much water once they are actively growing. Rain water, soft tap water or RO (reverse-osmosis) are best. If you have very hard tap water, this is OK but I would be cautious about keeping them too wet. If possible, keep them open to the weather in summer so they can be rained on. They love it! Personally I take the roof glass out of the glasshouse they are in so the rain can fall in on them. It also keeps them cooler. As days shorten in the autumn, growth slows and finally stops and the leaves start to go yellow. This is the time to reduce watering and as the leaf colour starts to go brown, stop watering altogether and allow them to completely dry out. The leaves will finally fall off and the pseudobulbs enter their dormant phase.
