When produce is grown in its proper season and under appropriate conditions, it exhibits all of its natural nutrients. Studies have shown that some crops can have up to three times more nutrients when grown in season. This is because seasonal fruits and vegetables don't have to endure as much travel, so they don't lose those vital nutrients.
It's simple, really. Food is easier to grow in its proper season, making it more abundant, less time-intensive, and more affordable for consumers. Often there will be specials on seasonal produce, because there is simply too much of it, and it needs to be used up!
Seasonal vegetables don't have to travel as far to reach their destinations, reducing the amount of fuel needed to transport them. What's more is that those out-of-season ingredients often undergo chemical washes and wax coatings in order to appear fresh during the long journey. Seasonal eating greatly reduces the need for these practices while reducing your carbon footprint.
A reduced carbon footprint, health benefits, and cost reduction are all great reasons to eat seasonally. But let's face it, at the end of the day, we all just want to eat delicious food. Food grown in season is significantly more delicious than food grown out of season. The flavors are stronger and more developed, the textures are as they were meant to be, and you end up appreciating them more.