Sedirea japonica orchids are one of the few orchids native to Japan, according to Botanica Ltd. They are related to the Aerides group of orchids, which are found in southeast Asia. Desirable for its especially sweet, powerful fragrance, this small orchid features creamy white blooms with purple markings. Like all orchids, the health of this plant depends in large part how much time the home gardener is willing to devote to care practices. Sedirea japonica orchids need consistent culture in order to thrive.
Place your Sedirea japonica orchid in a location where it will receive bright but indirect sunlight, or morning sun, such as an east- or south-facing window. The hot rays of the afternoon sun can scorch the plant's long, thin leaves.
Keep the daytime temperatures consistently warm, between the high 60s and low 80s F, with a drop of 10 degrees in temperature at night. This drop in temperature is necessary for blooming, according to the University of Illinois Extension. Do not place the orchid near any drafts, such as hot air from a heater vent.
Provide humidity for your plant. Orchids in general need at least 50 percent humidity in the air in order to thrive, according to the American Orchid Society, and S. japonica is no exception. Place the orchid on a humidity tray (a tray filled with pebbles and water) or run a humidifier nearby for a couple of hours each day.
Water your orchid when the planting medium begins to dry out. Use a planting medium that has large amounts or sphagnum moss, or one mixed especially for orchids. Use rain or distilled water when watering, as tap water can contain a high amount of salts and minerals.
Fertilize your orchid every other watering during the growing season (spring through summer), and every two weeks or so in the winter, according to the American Orchid Society. Use a fertilizer formulated for orchids and follow the instructions as per the age and size of your flower.