All of that can be replaced by foreign sources.
China alone can replace the walnut production, along with apples from washington state, and cherries from michigan.
Almonds, olives, and nuts can come from the middle east.
Greens, tomatoes, onions, peppers, and potatoes are abundant in central-south america.
The point is, food processing and sales industries are a global business. The number of US based and owned growers, producers, and processors are dramatically shrinking.
It wasn’t just those nasty manufacturing jobs that went overseas.