If planned out right (and with some cooperation from Mother Nature) you can have a bountiful of harvest up to Thanksgiving in southeastern Pennsylvania without any protection.

As temperatures begin to fall, lettuce, root crops and other miscellaneous greens start to thrive. The goal is to have these crops relatively mature before freezing temperatures set in. This ensures they will be able to hold up to the light frosts of October/November. Best of all, many of the vegetable crops develop better flavors when hit with some of these frosts. Plants store up more sugars to help protect themselves from these colder temperatures. 

Check out these pics of what we have growing here in our garden.