The best results for preserving calla lilies can be obtained by using silica gel. Harvest the flowers in the morning. Trim the stems to within half an inch of the flower. Pack the flower in silica gel in a container, completely covering the stem and the inside and outside of the blossom. Place a lid on the container, and store it undisturbed for two weeks before checking the flower.
When drying calla lilies, do not allow the sides of individual flowers to touch. The blooms shrink during the drying process, so it is wise to dry more than are needed.
The calla lily is native to Africa. It's a very popular wedding flower, with large, white, trumpet-shaped blooms. First named by the famous Swedish botanist, Carolus Linnaeus, the calla lily isn't actually a lily. It belongs to the zantedeschia genus, which contains 28 different species. Hardy in U.S. Department of Agriculture zones 8 through 11, calla lily rhizomes must be dug up in colder climates and brought inside for the winter.
Calla lilies can be grown in almost any type of soil. They prefer humid environments and spread easily, being considered a weed in some areas. Bulbs can be dug up and replanted for propagation.