Keep in mind that the gardenia (Gardenia) you purchased was grown in a greenhouse with ideal light, humidity, and fertilization. It's virtually impossible to duplicate those conditions at home unless you keep your gardenia in a greenhouse or conservatory. So you shouldn't expect as much bloom as when you first got it. But with proper care, you can get your gardenia to bloom again. Gardenia prefers temperatures on the cool side-about 70 degrees Fahrenheit during the day and 60 degrees Fahrenheit at night. Flower buds may not set if it is too warm. Gardenia also needs a bright, sunny location indoors to set flower buds. (Outdoors, partial shade is better.) Low humidity is another bane of gardenia flower buds. Keep the humidity high around your gardenia, or flower buds will abort. Group it with other plants, use a humidifier, or set it on a pebble tray with water at the base. Fertilize through the spring and summer with acid fertilizer (evergreen and azalea food).