It does extend the season for regular crops. I understand that it can make it possible to grow cool weather crops like kale and carrots well into the colder months. I don't know if they actually continue to grow or if they just don't die off. I know that carrots are good until the ground freezes. I've heard of people covering the carrots with straw to keep the ground from freezing around them when they're in a row cover or hoop house. I guess that way, they don't have to harvest them all at once, but can leave them in the ground until they want to use them. I don't know how well that would work up here with our winters, but it might work where you live. I suppose it depends on how cold it gets at night and how much ground freezing you get.
RE: My $288 Green House!!!