Osmocote can be used around your potted azalea and the amount depends on how large the container is. For an average size 5 gallon pot if the azaleas is at least one foot by one foot apply 2 tablespoons of Osmocote. Use less on smaller plants, more on larger ones. You don't have to be exact as Osmocote is realized slowly as the soil heat up in the summer so if you follow the instructions on the label there is no risk of burning the leaves of the azalea due to too much plant food. Keep growing, Marianne Binetti