Gardenias need full sun to thrive. When outdoors keep your Gardenia in a container so it is easy to move to a sunny spot. Providing morning sun and afternoon shade is best during the heat of summer. But on cooler days full sun is preferred.
Indoors, keep your Gardenia in front of a sunny window that gets at least 6 hours of sun a day. Note that your plant may not bloom while indoors.
Gardenias need to stay consistently moist. If outdoors they need at least one inch of rainwater each week, or the equivalent if you are hand watering. Gardenias will not tolerate drying out, so check the soil daily and water when the top layer is dry to the touch. If given too much water your plant may not bloom or even start to drop buds. Indoors Gardenias may not need as much watering but still monitor the soil regularly.
Use a diluted fertilizer for acidic-loving plants every 2-4 weeks during the summer. Do not fertilize during the winter.