Red Alert Calla Lily Bulbs - 5 Bulbs The Brightest Red Calla Lily of all!! Excellent Cut Flower! Height 18-24 inches, Zone 7-10 We have overwintered these at our nursery in zone 6b quite well by planting them a little deep, and mulching well. Do not try overwintering in pots out of the appropriate zone. Please note: Our shipping occurs only one time for up to 5 items, so please check out all our plants and bulbs to make the most of your shipping dollar