I just found out about CSAs - Community Supported Agricultural farms. Consumers buy shares of the farm and receive fresh produce and other farm products throughout the growing season (usually 16-20 weeks starting in May). Many of the farms use organic growing methods which is much better to the environment than other methods. They don't have to use preservatives because they deliver their products fresh to the local community. That also means they don't have to drive fuel-guzzling trucks around as much to deliver to their markets.
Here are a couple of sites that give more details including searchable directories of CSAs available in your area.