Humidity in the air is just as necessary as moisture in the soil. Some orchids, like Paphiopedilum, need as little as 40% humidity and other types need as much as 80%, whereas an average home in the northeast may have humidity as low as 25%. Both heating in winter and air conditioning in summer remove a lot of moisture from the air. Supply extra humidity with humidifiers, or group plants on a gravel-lined tray that is filled with water to increase air moisture through evaporation. You can use a simple hygrometer to assess the humidity and keep it in the  range that your orchid prefers. Humidity should be kept higher at the warmer end of the temperature range and lower at the cooler end to prevent problems.

Some orchids, like Phaleanopsis, can manage with lower than optimal humidity but those conditions decrease the likelihood that your plant will re-flower successfully. You can find information about the best humidity range for your orchid in our Guides to Caring for Orchids.

Gentle air movement is advisable when higher humidity is needed by such orchids as the Vanda species. A small fan can be used for home orchid growing, placed in a room not directed on the orchid, but to move air flow around, especially when high humidity is also provided.

For tips on a variety of gardening topics, see our Plant Information Guides.
- Courtesy of NYBG Plant Information Service