We direct seed delphinium species in field seed beds and also volunteers show in bed , all survive at least 15 deg F cold spells. Although not D. nudicaule. Pots might be different since they should not freeze solid, best buried in soil or mulch. Rich Haard Bellingham On Dec 29, 2011, at 3:09 PM, Kathleen Sayce wrote: > I have Delphinium nudicaule seedlings popping up their cotyledons, and wonder if I should put the pot in the cold frame. Or are they tough enough to prefer winter outside, in a wet zone 8 location. > Any suggestions? >