Light:
Gardenias prefer bright indirect light but not direct summer sun.
Water:
Gardenia’s do not like to dry out so keep their soil moist but not wet. Let the top inch of soil dry in between waterings. Gardenia need humidity and most homes are too dry for them to flourish. Keep them on a tray of water with a layer of pebbles. Do not let the gardenia itself sit in the water. As the water evaporates it will create humidity for the plant
Temperature:
During the day, Gardenias prefer temperatures from 20ºC to 23ºC degrees, with a low of 15ºC at night. If night temperatures are over 18ºC or below 15ºC, flower buds will not form.
Fertilizer:
Feed Gardenias every three weeks during the growing season with an acid-based fertilizer.
Potting
Gardenias do not need repotting very often, they like to be kept slightly root-bound, repot when roots are coming out the top of the plant. Use a well-drained, acidic soil is ideal for Gardenias, whether potted or in the ground.