Frit raddeana can survive temperatures down to 0F in December here, and nearly as low in February. These temperatures are rare, but do happen here, and I had no serious damage to Fritillaria raddeana growing outside in a pot plunged in sand, open to the elements. Peter (UK) On 19 February 2017 at 20:08, Jane McGary <janemcgary@earthlink.net> wrote: > > > On 2/18/2017 7:47 PM, Bob Nold wrote: > >> F. raddeana almost always freezes here. In my experience, its foliage is >> much more tender than that of F. imperialis, stenanthera, sewerzowii, and >> maybe eduardii. >> > When I mentioned that "moderate freezing" would not damage the plants, I > meant temperatures down to about 20 degrees F (about minus 6 C). Much > colder temperatures are likely to occur in Denver, Colorado, where Bob > lives. > > All my plants in the covered but open-sided bulb house (Mediterranean > house) recently experienced more than a week of constant sub-freezing > temperatures, but I see little damage so far. The open garden had about 30 > cm of snow on it at the time, so the smaller plants were well protected. I > think the survival of the bulb house plants is due in part to their foliage > being dry, and in part to the fact that they're in the ground in raised > beds or.... >