Caladium bulbs are the food storage organs of the Caladium, or elephant ear, plant, a colorful native of South and Central America. Most caladium bulbs for ornamental planting are now grown in Lake Placid, Florida, in the United States, which distributes bulbs all over the world. These bulbs can be used to produce new plants in ornamental gardens, and are a more reliable propagation method than seeds. This plant prefers open areas of forests and river banks and goes dormant, losing its brightly-colored leaves, when insufficient water is available. It prefers warm, damp environments with bright, indirect light.
Like other bulbs, caladium bulbs resemble overgrown roots, but are actually short, rounded stems that keep the plant alive during the dormant period. These bulbs are made up of scales, or modified leaf bases, that form a series of thin layers around the central core. The bulb swells with starches and sugars during the vegetative phase and shrinks during cold or dry weather, during which the plant uses the stored food to survive.
The caladium plant is originally native to South America, especially Brazil, as well as parts of Central America, but most commercially-produced bulbs are now grown in Lake Placid, Florida, which has been called the “Caladium capital of the world.” This US city produces a wide range of caladium varieties, including a range of fancy-leaved plants or various colors and dwarf cultivars. While wild caladiums usually have leaves that are mostly green, these fancy garden varieties can be bright pink or speckled with red and white, and may have almost no green areas at all.
Bulbs for garden use are shipped in the dormant state and planted when the temperature is at least 50° Fahrenheit (10° Celsius) at night. They produce foliage relatively quickly in the correct growing conditions, and the new bulbs can be saved for regrowth the next year, but may produce a slightly smaller plant. White-foliaged caladium bulbs work the best for gardeners who wish to save their bulbs from one year to the next.
Caladium naturally grows in open parts of the forest or on the banks of rivers, where indirect sunlight and water are readily available. If the weather gets too cold or dry, the plant enters a dormant state, losing its leaves and drawing all its nutrition from the bulb. The caladium will resume growth once conditions improve. To keep caladiums attractive all year, gardeners in cold climates may need to plant them in pots and bring them indoors when the weather becomes inhospitable.