Frost Hardiness of Zantedeschia

Most Zantedeschia species and hybrids do not tolerate frost, and even minor exposure to sub-zero temperatures is lethal to their tubers. Due to the lack of frost hardiness, the primary agronomic practice in regions with freezing soil remains the annual lifting of tubers for the dormancy period and storing them in areas with positive temperatures.

The exception is the species Zantedeschia aethiopica, which is capable of overwintering in open ground in the mild climates of USDA zones 8–10. In zone 7, overwintering is only possible with the use of mulching and the presence of specific microclimatic conditions, although the probability of plant damage remains high.