In addition to trying to buy and eat produce and grocery items from local farmers and merchants, it is important to try and eat seasonally as much as possible. Eating seasonally minimizes the amount of pollution and environmental hazards that occur when food has to travel a great distance to get to you.
Supporting local farmers and businesses that grow the right crops for the environment you live in at the right times is important to sustainable farming practices and the health of the environment. Many times, vegetables and fruits that are grown thousands of miles away are picked way before they are ripe, so they get to you before they go bad. Picking some foods too early and allowing them sit around for longer periods of time can cause those foods to lose some of their necessary nutrients, and there is some research out there (on Vitamin C and broccoli) that shows seasonally-grown produce might actually contain more nutrients than produce grown out-of-season. Why is this? It’s likely the weather. Temperature and precipitation play a huge part in the production of those essential nutrients.
I also think produce grown locally and seasonally tastes better than any conventional or organic produce I’ve had. Organic Washington-grown apples, to me, taste better here than they ever did in Colorado.