Every known variety of calla lily produces breathtakingly beautiful, showy, funnel-shape spathes, which are really colored outer leaves that encircle the spadix. The spadix, though small and difficult to see, is a tapering enclosure for the actual flowers. It is the prominent outer colored leaf structure that most think of when referring to calla blooms, which are supported by thick, strong, fleshy stems.
Although all callas are accented by rich green, long, sword- or arrow-shape leaves, many feature speckles or blotches of silver, white or cream, particularly the dwarf varieties.
The largest callas grow as tall as 7-8 feet, while dwarf specimens may be only 18 inches. No matter the size of the callas, all produce stunning, fleshy, waxy, long-lasting blooms, whether cut or allowed to remain on the plant to dramatize a garden setting.
Highly adaptable plants, some varieties of calla lily can even tolerate a mild frost. In United States Zones 6-10, most varieties may be grown outdoors year-round wherever the ground does not freeze. Some of the less cold-hardy specimens should only be placed outside all year in Zones 8-10. However, all of the calla lilies can be successfully grown as house plants.
Strong, sturdy and flexible, the calla manages to adjust to almost any soil conditions as long as the humidity is high enough. The plants will spread far and wide prolifically by means of rhizome offsets, and will quickly fill an area with beautiful blooming ground cover. Although it is possible to grow calla lilies from seed, it is a difficult, painstaking and usually doubtful process that takes a deal deal of time and effort. It is much easier to dig up rhizomes from existing Callas and replant some of them to repopulate another area of the garden.
Calla lilies prefer full sun in cooler climates, and partial shade in warm areas, where they can remain planted year-round. After the leaves wither, northern calla lily rhizomes should be dug up.
Storing calla lily rhizomes is a matter of just burying them in an open container filled with vermiculite, perlite or peat moss. They store easily in dark, dry, cool locations, and will be ready to plant in the spring when the frosts have passed. The rhizomes can also be divided while they are in storage.
When replanting calla lilies, a good feeding of 5-10-5 or 5-10-10 fertilizer should be given. Providing a moist, but not wet, well-drained soil will make the callas feel right at home, and will lavish the garden with spectacular rewards.
Warning for pets...
The calla lilies have but one flaw, which is that all parts of the plants are highly toxic if consumed by people and pets. All members of the calla family contain a poison known as oxalic acid. If ingestion is suspected, a poison control center should be contacted immediately. Early symptoms of poisoning include irritation and swelling of the mouth and throat, as well as acute and severe vomiting and diarrhea.
