Greetings from a lurker: Hymenocallis caribaea grew in the hundreds in USDA zone 8 on Galveston Island. Despite the zone 8 designation, temperatures fell to single digits during the 5 years we lived there, and usually fell to the upper teens in a 'normal' winter. The foliage would be killed off but the bulbs were unharmed. Below freezing temperatures usually lasted less than a couple of days, but cold spells with temperatures in the mid-30 to 45 degree F range could last for weeks. The soils were silty sands and the permanent water table (brine) was about 18" deep. These plants were about 150 feet from open water and part of foundation plantings around some of the older buildings at the University of Texas Medical branch at Galveston. Boyce Tankersley btankers@chicagobotanic.org