Cala lily, California
image by http://flickr.com/photos/angela7/128038715/
The calla lily is a summer-flowering bulb which blooms in shades of white, yellow and pink. In tropical climates, where winter temperatures stay above 55 degrees, the bulbs don't need to be removed from the ground and should flourish year round. In moderate climates, you may allow the plants to die back during winter and return in spring. In cold or wet climates, calla lily bulbs must be removed from the ground in late fall and stored until late spring.
Notice when your calla lily is ready to be stored in late fall before the first frost. Its growth will slow and its leaves will start turning yellow.
Dig down gently 2 to 4 inches to the bulbs, using a hand shovel. Handle bulbs carefully to prevent bruising. Wash or rub off excess dirt from bulbs.
Dry calla lily bulbs outdoors several days. If they're too moist during storage they could get a fungus disease.
Put them in a paper bag. Paper allows air circulation to prevent molding. Store them in a garage, basement or other cool, dark and dry place where the temperature remains between 45 and 60 degrees F.
Replant calla lily bulbs in late spring when temperatures remain above 55 degrees during day and night. Grow them in indirect sun in warmer climates and direct sun in cooler climates. Keep soil moist but don't over water.