Gardeners who grow gardenias tend to have a love-hate relationship with the plant. It can be temperamental, demanding and confusing. Then, when given exactly what it needs, it will die, for no apparent reason. But, one whiff of the intoxicating smell of the gardenia flower on the shelf at the nursery, and it's love all over again. Gardenia is a tropical flowering shrub that will need some shade on hot afternoons and an acid soil in order to thrive. The gardenia, hardy to USDA zones 9 to 11, is easy to deadhead and should be done after the blooms have turned brown and died.
Grab a branch toward the middle of the gardenia bush and pick off the dead flowers. You can either pinch them with your fingers or pull them off. Make sure to carry the bag with you and dispose of the flowers as you pick them. Any dead flowers left on the ground provide breeding places for pests.
Move, branch by branch, toward the outer part of the gardenia bush, picking off dead gardenias.
Work your way around the bush, from the middle to the front until all dead gardenias are gone. Properly dispose of the bag of dead gardenias.