When do you bring in for winter? At what temp for least shock?

If you live in a USDA zone where frost-proof gardenias cannot thrive outdoors during the winter, you should bring them indoors before the first frost. Ideally, bring them inside when the nighttime temperatures consistently drop below 45°F (10°C) to minimize shock to the plant. Gardenias are sensitive to cold, and the shock of sudden temperature changes can be detrimental to their health. When transitioning them indoors, place them in a bright, cool room with temperatures between 55°F and 65°F (13-18°C). Make sure they receive adequate sunlight and maintain their regular care routine during the winter months.