The graceful, curving blooms of calla lilies (Zantedeschia spp.) are a staple at florists, and make an attractive addition to your own home-grown bouquets. Callas grow outdoors in U.S. Department of Agriculture plant hardiness zones 8 through 11, and in other climates you can treat them as an annual or dig up and store the bulbs indoors over winter.
You can cut callas any time while they're in bloom, but it is best to cut them on the day they open. They'll last longer if you cut younger blooms, so make sure you cut callas before the pollen on the stalk in the center of the flower starts to shed.
Use a clean, sharp tool to cut calla lily flower stems. Make cuts near the base of the plant, so the cut stem won't be sticking up. Removing flower stems does not hurt the plants. The only other pruning that calla lilies require is removal of leaves as they turn yellow and die.
Always sterilize cutting tools before use on calla lilies. This prevents the spread of disease and dirt that could damage the plants, or make the cut flowers wilt faster. Mix a solution of 1 part bleach or pine oil cleaner with 3 parts water, then soak the tools for five minutes. Rinse disinfected tools with clean water before use.
As soon as you cut a calla lily stem, place it in a container filled with 2 inches of lukewarm water. Take a container with water in it out with you to the cutting garden.
The water in this container, and in the container you use when arranging calla lilies, should contain a flower food solution. These are available commercially in garden centers and craft stores, or you can make your own. Mix 1/2 teaspoon sugar, 1 teaspoon of lemon juice, a few drops of bleach and 4 cups of water to make a flower food substitute.
Wrap an elastic band around the bottom of each flower stem when you place it in the water. This keeps air bubbles from traveling up the stems and increases the vase life of calla lily flowers. Leave the band on for one hour, then remove it and let the callas sit in the water for one more hour before you start arranging them.
When you're ready to arrange callas, pour 2 inches of a water and flower food solution into the vase. When you cut calla stems to the desired length for your arrangement, make all cuts underwater. Only remove the stems from the water when moving them from one container to another.
Calla flowers should last for seven to 10 days after cutting. Check the water level in the vase daily, and add a flower food and water mixture as-needed to keep the water level at 2 inches deep.
After graduating from The Ohio State University, Marissa Baker turned her attention to professional writing. Her experience covers a variety of topics, including gardening, landscaping and lawn care equipment. She has been gardening for as long as she can remember, and writing about garden and lawn care since 2012.