A walk through the produce section of a supermarket might leave you thinking we can have all kinds of delicious and nutritious fruits and vegetables year-round,at least until you actually bite into that January strawberry from South America.
These days, most produce in supermarkets comes from California, Florida, and other states with longer growing seasons, or is shipped in from other countries thousands of miles away. This is true even in the spring, summer, and fall, when local fruits and vegetables are available.
In order to survive journeys of over a thousand miles, most produce comes from varieties that have been bred for durability rather than flavor and nutrition. Most produce is also picked before it's truly ripe because ripe fruits and vegetables are more easily damaged in transit and rot more quickly. Unripe produce, however,hasn't yet reached its peak of flavor and nutrient content. Moreover, fruits and vegetables begin losing nutrients as soon as they're harvested, so more time spent in transit means less nutritious food.
Different vegetables and fruits have different seasons depending on locale. In the Mississippi River valley area, for example, lettuce usually becomes available in late April, new potatoes are first available around the end of May, the earliest field tomatoes ripen in late June (greenhouse varieties are often available earlier), and sweet corn only gets to be "sweet" about the beginning of July. Strawberries, raspberries, blackberries, and blueberries each have growing seasons of a few weeks to a couple of months during the summer, depending on the weather (though they also freeze well), peaches come on a bit later, and apples and pears ripen as the signs of Autumn appear.
Consequently, eating more locally-grown foods also means eating more in tune
with the seasons. But, while this entails not being able to eat whatever you want, whenever, it also means never having to suffer the culinary disappointment of biting into a dry, flavorless tomato. Perhaps most importantly, farmers growing for local markets are much more likely to grow varieties that were bred for flavor and nutrition rather than durability and a long shelf-life.