I grew Dichelostemma species for some years with winter temperatures fluctuating to a minimum of around minus ten C. my method was to plant the corms deep in pots of sandy compost topped with gravel. The pots were plunged in sand with overhead rain protection. They would have frozen solid on occasion but survived until a winter with lows of ~ minus 15 C. the trick was to keep them dry until early spring so that they did not freeze much while in growth. extra feeding was required to compensate for the shortened growing season. My sister also grew "Fire Cracker" in a very well drained bed for three years in a rather colder winter micro climate with dry summers. It died out with her after a wet Summer followed by the same cold winter. Peter (UK) On 14 March 2014 04:57, Eugene Zielinski <eez55@earthlink.net> wrote: > I was able to bloom Dichelostemma ida-maia once when I lived in central > Pennsylvania. The bulbs were from a commercial source and were planted in > the fall. The plants came up in spring and bloomed in June. Central PA is > classified as zone 6 (minimum temperature 0 to -10 F), but I believe the > temperatures were not that cold that winter, more in the zone 7 (10 to 0 F) > range. > The plants did not reappear the following year. I'm sure it was because I > planted the bulbs in an area where they did not get a chance to dry out > over the summer. >