Interesting, thanks for sharing your experiences with the garage. I wonder what the coolest temp a cyp parvifloum would suvive for vernalization. The ground does freeze solid where we are!
Debile is a cute little one!
In the past I have actually had hardy species (parviflorum and reginae) planted in the ground perish over the winter when they were not mulched. In these cases I assumed it was the lack of mulch that killed them because I plant them very shallow to avoid rot (I've had my share of cases of basal rot in the spring too!). It seems like the ground is not frozen as much or as deeply if a few inches of mulch cover it, especially with good snow cover. When the plants are otherwise reasonably planted (i.e. good soil, location, etc.) a good mulch guarantees survival over the dormant period, at least in my experience.
It would be interesting to see some actual numbers on what temperatures they tolerate at the roots during dormancy. All of the literature says not to ever freeze the roots, implying that even 0 C is too cold. Some sources more specifically say that they shouldn't be exposed to frost for
extended periods. This, I think, is the most accurate statement. I think that exposure to extreme temperatures such as what would have existed for a week or two in my garage this winter would spell doom, but I suspect that occasional and brief exposure to temps of 0 C to -10 C would be okay. Just some of my thoughts...

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