As with planting, there’s not too much required for the care of calla lilies other than keeping them watered and fertilized. An adequate layer of mulch around the plants will help keep the area moist and free of weeds. Calla lilies require a dormant period once flowering has ceased. During this time, you should refrain from watering as much to allow the plant to die back. If you grow calla lilies in containers, cease watering and move the plant to a dark area once the foliage has faded. Regular watering can resume within two to three months. Although calla lilies can remain in the ground year-round in warmer climates, they should be lifted and stored in cooler areas.