Culture
Winter hardy to USDA Zone 8, and may survive some Zone 7 winters with protection. Plant rhizomes 3-4” deep and 12-18” apart in spring after threat of frost has passed. Best in moist soils with full sun to part shade. Prefers part shade in the St. Louis area. Lift rhizomes in fall and store in a damp medium such as peat or immediately replant in containers to overwinter as a houseplant. Calla lilies may be planted in up to 12” of water in mud at the edge of ponds or water gardens. In this case, the rhizomes could arguably survive a St. Louis winter if the covering water does not freeze to the bottom. May also be grown year-round in containers that must be brought indoors in winter before first frost. Overwintering containers placed near a window with bright indirect light can make attractive houseplants.
Noteworthy Characteristics
Zantedeschia aethiopica, commonly called calla lilies, are not true lilies, but are arum (Jack-in-the-pulpit) family members. They are stemless plants whose flowers and leaves rise directly from rhizomes. They typically grow in clumps to 24-36” tall and feature large arrowhead-shaped (sagittate) leaves and extremely showy flowers consisting of a yellow finger-like spadix surrounded by a bright white spathe borne atop a leafless stalk. Commercially grown as a very popular cut flower.
Genus name honors Giovanni Zantedeschi (1773-1846), Italian botanist.
Specific epithet means African, usually South African.
Problems
Rhizome rot. Japanese beetles may feed on the flowers/foliage.
Garden Uses
Borders, containers, pond peripheries, water gardens or houseplants.