I routinely set out flats of hardy geophytes (e.g., Corydalis spp.) in late fall and early winter, after average minimum temperatures have dropped below freezing. But first the planted flats (which are 16 inches square and 5.5 inches deep) spend at least 2 weeks in a minimally heated shed where temperatures stay above about 4 degrees C. I move the flats outside during relatively frost-free spells (this coming week looks ideal), and cover them with inverted 17- by 17 -inch web flats to ward off varmints (the air space between the cover and the surface of the planting medium also provides some insulation). Before the next boreal blast arrives, I mulch the flats with a 5 cm (or more) layer of Pinus strobus needles (or oak leaves will do in a pinch). Some species (such as Central Asian corydalis) almost seem to best under this regime. Russell in central Massachusetts, USDA Zone 6a, modified continental climate At 04:01 AM 12/2/2012, Peter wrote: >Frost has arrived here, any winter growing bulbs I now plant will be kept >on my coolest frost free window sill where they can root and pretend it is >still 'Fall'. They will be put outside, in appropriate frames, in early >spring, when well rooted. Russell Stafford Odyssey Bulbs PO Box 382 South Lancaster, MA 01561 508-335-8106 http://www.odysseybulbs.com/