California’s drought-plagued Central Valley hogs the headlines, but two-thirds of your winter vegetables come from a different part of the state. Occupying a land mass a mere eighth the size of metro Los Angeles, the Imperial Valley churns out abouttwo-thirds of the vegetables eaten by Americans during the winter. Major crops include broccoli, cabbage, carrots, cauliflower, and, most famously, lettuce and salad mix. And those aren’t even …