That's pure nonsense. We have trashmen here in St. Louis who are *not* illegal immigrants, and our trash gets picked up just fine. Pay agricultural workers a reasonable wage and Americans *will* do those jobs. If fruits and vegetables get too expensive, then that's more motivation for people to grow their own, or buy from local farmers and neighbors who *do* grow their own.
People can learn to mow their own lawns and change their own babies' diapers, too - it builds character.
Not gonna happen and you know it better than me. You cite a local example, macroeconomically, there is not enough Americans to do the job. In Russia they all build characters by growing there own fruits and vegetables, been doing this for decades.