There is an Osmocote made for acid loving plants such as the azaleas, camellias and gardenias you can now grow. It is called Osmocote ARC (for azaleas, rhodies and camellias) but if you cannot find this type of Osmocote I would recommend adding peat moss to the planting hole to make the soil more acidic and using the Osmocote Indoor/Outdoor all purpose formula. Keep in mind the shrubs you mentioned are not heavy feeders but fail most often due to soil that does not drain well in the winter, soil that dries out in the summer or too much shade that can prevent these plants from setting flower buds. They do need afternoon shade but at least two hours of morning sun will help all three produce flower buds. Keep growing, Marianne Binetti