The temperature range most often recommended for "warm growing" orchids is 55º to 90ºF (12.7º to 32.2ºC) while in practice most species will tolerate five degrees farenheit greater in each direction. Additionally, many sources will use wording like "plants can tolerate extremes outside of this range for short periods of time" often mentioning air movement and humidity. Many culture variables affect the actual temperatures a given orchid can withstand without stress. In general though, warm growing refers to humid, jungle-like conditions one would expect to find ear sea level in the tropics. Orchids are adaptable and the species presented here will grow outside of those ranges, however optimum growth will be achieved when grown warm.
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