I do not use pesticides on my Navel Orange Trees, are the leaves edible for food flavoring?
I use rich soil (composted) to fertilize the tree, it bears prodigiously, leaves are healthy, so are branches. I do trim it and also take off the water spout shoots; I keep it watered as needed by weather and/or condition.
Orange leaves are listed as non toxic to humans. If you are comfortable with your own tree leaves that they have not been sprayed with any insecticide, pesticide or fungicide you can use them.