Answer: Gardenias are so lovely -- it's no wonder they are a popular gift plant!
Gardenias grow outdoors in mild climates, and as an indoor houseplant in other areas of the country. With good care and a little luck, your plant will bloom every year. If yours is outdoors, place it in a spot that will be shaded from hot afternoon summer sunshine. (It can be very difficult to transition the plants to indoor growing after they have been used to being outdoors or in a greenhouse. The dryness and extremes of indoor heating tends to cause the leaves and buds to drop. The best you can do is to locate your plant away from heaters and heating vents and mist your plant daily.) If it's indoors, give it bright light, but not direct afternoon sunshine.
In order to bloom, your plant needs a nighttime temperature of 60F - 65F degrees and a daytime temperature about 10 degrees warmer. Without an even temperature and careful watering, gardenias will drop their flower buds while they're still unopened. Keep the soil moist using tepid, soft water, and mist the plant every day to keep the plant happy. Fertilize with a water soluble fertilizer for acid loving plants such as Miracid following the label instructions.
It's natural for the older leaves of gardenias to turn yellow and drop off. New leaves will grow in their places. To keep your plant tidy and to encourage new growth, pinch back the growing tips of the stems. Gardenias don't like to be repotted more often than every 2-3 years. Do so in the spring, using a good commercial potting soil for acid loving plants, and putting the plant in a new pot that's only slightly larger than the old one.
Gardenias are difficult to grow as houseplants and the simple shock of moving from the greenhouse to home can kill them. (Stress can also cause the plant to stop blooming or die back temporarily.) These plants require an acid soil mix and plenty of bright light with ample humidity and a moist but not soggy soil; often they will tolerate a short stay in the house during winter but then need to be returned to the optimum conditions of a conservatory or greenhouse in order to rebuild strength to bloom again the following year. In my experience it is really best to enjoy a gardenia as a "bouquet" without trying to keep it as a houseplant -- unless you have a greenhouse. It helps to think of gardenias as one-season plants and be prepared to replace them each year; that way, if yours thrives you will be pleasantly surprised.
Q&A Library Searching Tips