Growing gardenias indoors, within the confines of your home, requires close attention to humidity, light, and pest control. Indoor gardenias require cool temperatures, moderate humidity, and plenty of bright light to thrive. They do not respond well to being moved around. They should get at least half a day of direct sun, and be in a room with a temperature that is about 64 F. (18 C.) during the day and 55 F. (13 C.) at night. Moderating the humidity is especially challenging during the winter when the indoor heat kicks in. The drying nature of most heat can cause a once beautiful gardenia to fall to pieces, literally. There are a few ways to increase indoor humidity: The first is to group houseplants close together, the second is to spray a light mist of water on foliage during the early morning hours, and the third is to run a humidifier.
Keep your plant free of drafts and never place a gardenia where it will receive the direct force of hot air from a furnace. Provide water when the soil is dry to touch and add acid-loving fertilizer during the growing season. Remove woody stems to encourage prolific blooming. Monitor for insects.