Cut off the welfare checks to all able-bodied freeloading Americans and watch as they suddenly find themselves motivated to work.
That's Step #2. First, deport the illegals, then you'll have crops to pick.
Of course, the real reason they are struggling for labor is not that there aren't enough illegals, but that the illegals that are here have moved into higher-paying lines of work, such as construction and roofing.
Bump that!
If enough people get hungry, they will get up off the couch and go out to pick vegetables...