What produce do the California farm provide the bulk of national supply?

Produce produced 75%+ in California: Artichokes, Lettuce, Celery, Tomatoes (processing), Grapes, Peaches, Lemons, Apricots, Cherries

Produce produced 50–75% in California:Carrots, Spinach, Broccoli, Cauliflower, Asparagus, Pears, Peas, Pumpkins, Chickpeas, Oranges

How many California farm workers are foreign-born; how many unauthorized?

The USDA’s national crop workforce estimates as of January, 2025: “In 2020–22, 32% of crop farmworkers were U.S. born, 7% were immigrants who had obtained U.S. citizenship, 19% were other authorized immigrants (primarily permanent residents or green-card holders), and the remaining 42% held no work authorization. The share of workers who are U.S. born is highest in the Midwest, while the share who are unauthorized is highest in California. (Also go here.)

A much-cited profile of the California workforce estimates that 49% of the state’s agricultural workforce is foreign-born and that 42% of these workers are unauthorized. Thus, close to a quarter of the state’s agricultural workforce is unauthorized. Other estimates are that 70% of the workforce in selected produce sectors (such as grapes, almonds and strawberries are foreign born. One can reasonably infer that the unauthorized share of selected workforces exceeds 50%.