Zygopetalum orchids (often called "zygos") are terrestrial orchids. There are 15 known species of zygopetalums, which are native to South America, according to Beautiful Orchids. These showy flowers are highly desirable for their blooms, which last longer than many other orchids and are often used in cut flower arrangements. Caring for zygopetalum orchids requires consistency on the part of the home gardener.
Keep your zygopetalum in a cool location. The tropical beauties thrive best in temperatures averaging in the mid 60s F, according Texas A&M University. In fact, they will suffer if exposed to hot sunlight, so keep your orchid well away from hot windowsills. And never expose it to freezing temperatures.
Never plant zygopetalum orchids in rich, loamy potting soil. Instead, choose a planting medium made especially for orchids. These usually contain tree bark, peat moss and other "soilless" ingredients.
Zygopetalum orchids need light to bloom, but not direct sunlight. Filtered or dappled light is best, according to Texas A&M. A minimum of six hours per day is needed. Watch the leaves of your orchid to see if it is getting too much or too little light. Yellow leaves mean the flower is being exposed to too much sunlight, while leaves that are a deep green mean the plant could use more light.
Water and Humidity
Place your orchid on a humidity tray to give it the humidity it needs to thrive. Make your own humidity tray by filling a shallow tray with pebbles that are barely covered by a layer of water. Keep the soil barely moist, but not soggy; this can lead to root rot. If the leaves are turning yellow, water more frequently.
Zygopetalum orchids thrive with a monthly dose of food. Use an orchid fertilizer that is high in nitrogen during the months of February through July. From August to January, use a fertilizer that is low in nitrogen. Follow the directions on the label for application.