Callas (Zantedeschia) are adaptable; they thrive in the ground or in containers. I prefer containers because callas look good as container plants and are easier to store over the winter that way. (These plants are frost-tender, so they need to be put in storage in autumn.) To plant them, fill a large pot with good-quality potting soil and set the rhizomes about 4 inches deep. Water well and place the pot in partial shade. Callas accept sun or shade but do best in a location that gets bright, filtered light. Because they are tender, do not plant them outside until all frost danger has passed. You can also easily grow callas directly in the garden. Select the same growing conditions and plant them at the same depth as though you were growing them in containers unless your garden has heavy soil. In that case, plant them only 2-3 inches deep. In autumn, dig and store the bulbs in a frost-free place.