Calla lilies have tightly furled flowers on tall stalks that grow up above deep-green leaves. The flowers may be white, yellow, rose or burgundy; the leaves of some varieties have white spots on them. A native of South Africa, the calla lily is a great favorite for cut flower arrangements, but many gardeners grow them in flower beds and containers. Calla lilies bloom late in the summer, when many other flowers have stopped flowering.
Plant your calla lily rhizomes after the danger of frost has passed. To be on the safe side, call your local county extension office to find out when the last average frost date is in your area.
Pick a spot to plant your lilies where they will get bright morning sun and some shade in the afternoon.
If you're planting the lilies in a flower bed, spade the soil in the bed well and mix in plenty of organic material such as compost to give the flowers good drainage.
If you're planting calla lilies in containers, fill the pots with a mixture of potting soil and organic materials.
In a flower bed, plant the rhizomes four to six inches deep and a foot or two apart. In containers, plant them at the same depth, but six to 12 inches apart. In either case, cover the rhizomes up well with soil and then water them thoroughly.
Be sure to fertilize your lilies every month and keep watering them regularly. Weed them carefully, as well.
If you live in U.S.D.A. zones 8 or 9,you can leave your calla lily rhizomes outdoors over the winter. (See the USDA Hardiness Zone Map at: http://www.usna.usda.gov/Hardzone/ushzmap.html). Cover them up with a good layer of bark or straw before it frosts for extra protection.
If you live in a colder area, leave the rhizomes outdoors until it frosts, and then dig them up, clean them off and take them inside. Let them dry for a week or two in a cool, airy spot, and then move them to a shed or garage where the temperature stays between 50 and 60 F. When the weather warms up the next spring, you can plant the rhizomes.