The locavore ideal is a world without trade, not only beyond national borders but even from the next state: no Florida oranges in Colorado or California grapes in New Mexico, no Vidalia onions in New York or summer spinach in Georgia.
Fully realized, that ideal would eliminate one of the great culinary advances of the past half century. Unripe peaches notwithstanding, today's supermarket produce departments are modern marvels. American grocery shoppers have choices that would have been unimaginable only a few decades ago. When I was growing up in the 1960s and 1970s, the only way to get fresh spinach or leaf lettuce was to plant a garden. Avocados were an exotic treat, asparagus came in a can, and pomegranates existed only in books.
Now my neighborhood supermarket sells five types of lettuce, plus spinach, endive, escarole, radicchio, frisée, rapini, three kinds of chard, mustard greens, dandelion greens and kale. That's not including all the cabbages—or, of course, the prewashed salads in a bag that have particularly boosted fresh-spinach purchases. In this ordinary produce department, you can buy not only avocados, asparagus and pomegranates, but everything from purple baby cauliflowers to spiky kiwano melons that look like some kind of scary deep-sea creature. Need portobello mushrooms, Japanese eggplant or organic ginger at 2 a.m.? The store is open 24/7.
There's no question but what eating fresh, local produce at harvest time provides taste and texture that commercial food rarely equals. But, of course, the rest of the year -- unless you live in Florida or California -- the dining alternatives will be reduced to canned tomatoes, potatoes from the root cellar and the odd serving of venison steak your neighbor brought over.
The militant locavores (who all seem to live in Mediterranean climates, oddly enough) never mention that. But, please, read the whole thing and please do check out the comments.