Tropical-looking calla lilies (Zantedeschia spp.) are native to Africa. Their waxy, trumpet-like flowers, which are technically modified leaves, emerge in shades of white, red, yellow and pink. Callas grow to heights of 30 inches or more.
The calla lily is technically not a lily. True lilies have bulbs with basal plates from which roots grow. Calla lilies grow from rhizomes, which are thickened stems growing horizontally at or below the soil line. Underground rhizomes produce roots on their lower surfaces and send shoots above ground, the University of Florida IFAS Extension explains.
Calla lilies are available in several hues.
Calla lilies do not tolerate winter weather. After frost kills the foliage, carefully dig up the rhizomes, which resemble potatoes, and remove loose soil, says the University of Minnesota. Cut the stems and foliage back 2 to 3 inches, hose off remaining soil and let the rhizomes air dry for a few days. Store bulbs in a paper bag in a cool, dark area, such as the vegetable bin in a refrigerator, where temperatures stay between 40 and 50 degrees Fahrenheit.
Divide rhizomes in the spring. Cut where each divided rhizome will have an eye or growing point. Let the divided rhizomes dry for a few days before planting them, to allow the wound to scab, advises the University of Minnesota. This prevents harmful organisms in the soil from entering the rhizomes.