Planting a Calla Lily in a Pot
The calla lily (Zantedeschia aethiopica) is not a true member of the lily or Lilium family. They are rhizomatous summer-blooming plants, which are commonly grown like other summer-blooming bulbs, such as canna or dahlia. Calla lily rhizomes, which look somewhat like small potatoes, are planted in spring after the danger of frost has passed. By growing calla lily in a pot, in some locations, they can be started indoors earlier than they could be started outdoors. This can allow you to immediately place established, ready-to-bloom, container grown callas on the deck or patio earlier in the spring. Container grown calla lilies can also be planted early and manipulated to bloom in time for Easter or spring weddings. Another benefit of growing calla lilies in pots is that in garden beds in their ideal climate callas may naturalize, take over, and even become invasive. Container grown callas are restricted to pots and cannot become invasive. In cooler climates, potted calla lilies can simply be deadheaded, treated for insects, and then taken indoors for winter and grown as houseplants. Like other summer bulbs, calla lily rhizomes can also be dug up and stored in dry peat moss in a dry, dark location that does not get any cooler than 45 degrees F. (7 C.).
How to Grow Calla Lilies in a Container
Calla lily rhizomes grow best when planted 1 inch (2.5 cm.) deep and 1 to 2 (2.5-5 cm.) apart. Pots for calla lilies should be at least 10 to 12 inches (25-31 cm.) in diameter and well-draining. While calla lilies need consistently moist soil, improper drainage can cause rots and fungal diseases. The planting medium should also retain moisture but not stay too soggy. Container grown calla plants are usually watered when the first inch or two (2.5-5 cm.) of the soil is dry to the touch. They should then be watered deeply and thoroughly. Brown foliage tips can indicate overwatering. Calla lily in pots will also benefit from a general-purpose 10-10-10 or 5-10-10 fertilizer every three to four weeks in spring and summer. When blooming is finished, stop fertilizing. Calla lilies grow best in full sun to part shade. In containers, it is recommended that calla lilies be placed in a location where they can receive about six hours of sunlight each day. The ideal temperatures for container grown calla lilies are daytime temperatures between 60 and 75 degrees F. (15-23 C.) and nighttime temperatures that do not dip below 55 degrees F. (12 C.). If potted calla lilies are taken indoors and grown as houseplants through the winter, these ideal temperatures should be maintained.
