Calla lilies, also known as arum lilies, are a species of flowering herbaceous perennials native to Africa. Although the calla lily is not a true lily, it is similar in appearance. Calla lilies can grow up to 3 feet in height and bloom during late spring and early summer. The calla lily plant can be grown outdoors in most temperate regions, but require special winter care to survive.
Plant calla lilies during spring after the danger of frost has passed. Choose a location that receives full sunlight throughout the day. Spread 2 inches of organic compost over the planting site and use a garden tiller to incorporate it into the soil to increase drainage and fertility.
Water calla lily plants three times per week, or often enough to keep the top 3 inches of soil moist at all times. Check the soil once every two days to ensure the soil is kept sufficiently moist and apply additional water as necessary.
Feed calla lily plants once per week using a 20-20-20 NPK fertilizer. Water the soil before and after fertilizing to prevent root burn. Apply fertilizer according to the manufacturer's instructions for proper dosage.
Remove faded or dead flowers as soon as possible to prevent the calla lily plant from spending nutrients forming seeds. Pinch the flowers off as close to the stem as possible to minimize damage and new flowers will form shortly after.
Dig up calla lily rhizomes after the first frost of winter. Be careful not to damage the root system of the plant. Pack the rhizome in peat moss and store in a cool, dry room at a temperature of 50 degrees F. Replant the rhizomes in spring after all danger of frost has passed.