There are three temperature zones for orchids, and each type of orchid has an ideal temperature zone.
- Warm growers need daytime temperatures approximately 70°- 85°F /20°- 30°C. They enjoy a slight temperature drop at night, but should not go below 65°F /18°C. Warm growing orchids include Phalaenopsis, Vandas, Cattleyas, and most Dendrobiums.
- Intermediate growers need temperatures approximately 60°- 75°F /15°- 25°C during the day, with a drop of 5°- 15°F/3°- 8°C during the night. Intermediate orchids include Oncidiums, Paphiopedilums, and many Epidendrums.
- Cool growers need temperatures approximately 50°- 70°F/10°- 20°C, with a 10°- 20°F/5°- 10°C temperature drop at night. Many can handle temperatures as low as 40°F /4°C. Cool-growing Cymbidiums can handle a light freeze. Other cool growing orchids include Masdevallias, Miltoniopsis, and Odontoglossums.
Orchids Need a Temperature Drop at Night
All orchids require lower nighttime temperatures. Some, like Phalaenopsis, need just a 5°F/3°C drop, while others, like Cymbidiums, need as much as 20°F/10°C. These temperature changes allow daily cycles of chemical reactions to happen within the plant.