In North Texas, the winters are fairly mild. We’re zone 8a so the coldest it gets is high teens in January or February. But even that is too cold for potatoes. I had started growing potatoes in October (late but I had gotten busy with other projects) and was hoping that the row covers over hoops would provide enough protection until they were ready for harvest. Some were growing in the ground directly and others were planted in a 15 gallon grow bag.
We got some cold weather early this fall and even with the row covers, the potato greenery had died. So the potatoes in the ground got dug while I moved the potatoes in the grow bag to my small greenhouse.
The second image is from about 10 days ago. My potatoes are still growing and I’m hoping to get a harvest in a month.
My greenhouse is unheated. While the flooring adds some solar mass, the temps drop along with the outside but typically run about 5 degrees warmer in the cold evenings. I do put row covering material over the grow bag at night for added warmth and protection. So far, we’ve not dipped below high 20’s so if it gets colder than that, I may have to harvest early.
The advantage here is obvious. Being able to grow potatoes nearly all year round provides more high caloric foods for the table. And for those who are north of zone 8a, this approach can at least extend your growing season.