Temperature
Another difference between orchids and many houseplants is that in nature most orchids experience a big difference between day and night temperatures. Manipulating the temperature of the home so it will drop at least 10 degrees at night, especially in autumn and winter when many orchids initiate buds, will induce the orchids to set flower buds more readily. Achieve this by lowering the temperature on the thermostat. This little trick can mean the difference between an orchid plant that merely lives, and one that thrives and flowers. Orchids are usually classified as warm growing, intermediate and cool growing, with regard to their temperature needs. Many tolerate exposure to warmer or cooler temperatures without suffering damage. The temperature groupings refer to the lowest temperature the orchid prefers during winter nights. Warm-growing orchids, such as phalaenopsis, sulk if temperatures drop much below 60 F. Intermediate growers, such as cattleyas, prefer winter nights around 55° F. Cool-growing orchids, including cymbidiums and odontoglossums, are accustomed to winter nights of 50 F. At the other extreme, most orchids perform poorly when exposed to temperatures above 90° F.