Very interesting question!! The answer is.....some do and some don't.......probably pretty obvious!! But when trying to raise a crops (or keep crops going) the one major concern is not temperature (although that plays a roll) but light. When the days are shorter than 12 hours plants start to slip into dormancy mode. Even the cool weather lovers will slow their growth rates to minimal levels. This means that crops that are outside in the beds grow so slowly that even the cut and come again crops (like arugula) don't "come again." To make the question even more interesting.......no new sowing can occur.
The way fall/winter gardens are usually operated is as follows........plant sometime late summer and enjoy your bounty through november and december. January becomes the bleakest month for local veggies as even plants that can handle the cold are not growing.
This begs the question then......what about in the high tunnel? Right now we have numerous crops in the high tunnel including.....gator perpetual spinach, kohlrabi, beets, arugula, swiss chard, spinach, red russian kale, tatsoi, cilantro, dill, carrots, broccoli, lettuce, cauliflower, fennel, onions and chinese cabbage. Those of you that picked up a box this past week know that the arugula you are enjoying this week did indeed come out of the high tunnel!!! While there are NO references for Louisiana regarding growing in a high tunnel during the dormant season......it appears that the buffered climate (higher humidity and temps) offset a bit of the concern regarding light. The crops are growing as if they were planted under shade cloth (i.e. low light conditions). This is fine for some.....(your leafy greens) but may pose an issue for the root crops.
We have the ultimate quest to grow year round.........however, in these first few years of high tunnel growing it is like a big science experiment. Figuring out what we can and can't do. Hopefully some of the crops will make it to our plates soon!!!
Happy Holidays and we will see you all in 2012!!! And what a year it will be...........47 Daisies is going to be making a number of changes this coming growing season all to the benefit of veggie lovers......but those will have to be in another post!!!!
See you in the new year!!
Dylan and Harmony, whichever of us have the time to sit down and write for a few minutes. : )