As an experiment, I have already planted two grimo-natalina in ground this year. Both were rooted this past winter, so like I said .. an experiment.
One is next to house's south facing wall, the other out back in the little valley. Both will be getting lots of winter protection. The one by the house should be fine, getting radiated heat from the house, it should stay plenty warm enough. The one in the valley is a double experiment. First purpose is to check for fig tolerance/resistance to juglone excreted by the many walnut trees. Kind of like a canary in the mine. Second will be to test for winter hardiness, again with protection. I am hoping it will be fine as well. For winter use, root vegetables are often keep in ground under a heavy mulch. The ground does not freeze if mulched heavily enough, So I am hoping the fig will also survive.. Next spring will tell.
Grant
Z5b