HOW TO CARE FOR CALLA LILLIES IN VEGAS?

I recently moved to Las Vegas (zone 9-10) and I'm not sure how to care for my calla lilly bulbs in the extreme heat. Its only June but the leaves have all dried out and withered away. I've read about how the bulbs should be stored in cold climate to avoid freezing, but what about protecting them against extreme dry heat? Should I leave the bulbs in the ground or dig them up and replant next year? Any other tips on planting bulbs in the desert?