I have a gardenia bush that I received when my mother passed away. I have been keeping it in the house under a grow light but the leaves are falling off. Is possible to plant it now before the weather gets cooler?
Gardenias are only cold hardy to 20 degrees Fahrenheit. Whether you plant it outdoors or not depends on your winter temperatures. If you do plant outdoors, place it in a protected area that gets full sun to part shade.
Gardenias thrive in consistently moist, well-drained soil. Feed the plant in the spring before new growth starts using an all-purpose fertilizer.
As you have found, as houseplants gardenias can be temperamental. They require high humidity, consistent moisture, full sun and warm but not too hot temperatures. And they can be quite cantankerous even if you get the conditions right.
To help with the humidity set the pots in a tray of gravel and add water to the tray. As the water evaporates it will humidify the air. Avoid misting the leaves as this encourages fungus. Gardenias thrive on 68-74 degrees Fahrenheit temperatures in the day, and 60 degrees Fahrenheit evening temperatures.
If you move your potted gardenia outdoors for the summer, place it in an area where it will get afternoon shade and be sure to bring it back indoors before temperatures start getting too cool in the fall. Fertilize monthly with an acidic fertilizer. Gardenias are susceptible to insect problems so check often for signs of insects.