In order to get a gardenia to bloom, there are four things to remember about proper care. These are: humidity, sunlight, temperature, fertilizer. If your plant is in a container, setting the container on a dish filled with pebbles and water will help to increase the surrounding humidity. Whether your plant is planted in the ground or in a container, daily misting with a spray bottle will increase the humidity around the plant. Bloom best when the daytime temperatures are warm but not hot and the nighttime temperatures are cool. Ideally, for the day, want the temperatures to be between 18-24 C and between 13-16 C at night. Make sure that your plant is in an area where the temperatures will match this pattern. Proper feeding means that you should feed every two weeks with a regular water-soluble fertilizer solution, with an acid-based fertilizer.
Technical specification
Fertilizer: Universal fertilizer, liquid or granular
Blossoming season: Perennial plants, bloom throughout the season
Temperature: Full sun
Planting season: The most suitable time for planting is February.