Insert a garden spade or fork into the ground 2 to 3 inches away from the calla lily rhizomes. Wiggle the spade to remove the rhizomes. Lift the calla lily rhizomes out of the ground and lay them on several sheets of newspapers.
Divide large calla lily rhizomes into two plants or more. Cut the rhizomes with a sterile knife. Each rhizome section must contain roots.
Dig holes in the new location that are 4 to 6 inches deep and 12 inches apart. Make the holes twice as large as the rhizomes. Loosen the soil with a garden fork and place each calla lily rhizomes into a new hole. Plant it at the same soil level as its previous location.
Fill the holes with soil and press down on lightly to remove air pockets.
Water the calla lilies to dampen the soil. Continue to water the lilies with 1 inch of water a week, unless adequate rainfall occurs.
Apply a 2-inch layer of mulch around the lilies to keep the soil moist.
Apply a 5-10-5 fertilizer to the calla lilies in the spring. Follow the fertilizer instructions carefully.