Orchids are killed more often by the common mistake of over-watering than anything else. Phalaenopsis does not have a water storage organ like some orchids, so while restraint is essential, it is also important to not let it dry out entirely.  It needs to be watered when the potting medium has almost dried out. Watering frequency is likely to change during the year. Day length, humidity and individual heat systems will affect the rate at which water evaporates from the growing medium. Use your finger to test an inch or so down before you water. Moss potting mixture will dry more slowly than bark mix.

Always water in the morning. Orchids do best with water that has a low mineral content but Phalaenopsis is less sensitive than many other orchids and tap water is fine in most situations. Place the plant in a sink and allow the water to soak through and drain out completely. It is best to use tepid water, as it will help to dissolve fertilizer salts and not shock the plant. Bark potting mix initially repels water before it becomes saturated, so it is important to water until the bark is saturated.  Uneven watering will result in shallow or uneven root growth.

Humidity in the air is just as necessary as moisture in the soil. A minimum of 50% relative humidity is required to grow Phalaenopsis 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 65%+ range that Phalaenopsis prefers. 

Complete care tips provided here.

- Courtesy of NYBG Plant Information Service