Caladiums produce brightly colored foliage prized as houseplants or bedding plants. Native to Brazil and Peru, two basic types of caladiums are commonly grown: fancy- and strapped-leaved. Fancy leaf produces large, heart-shaped leaves in variegated colors from white and green to bright reds, maroons and rusts and reaches heights of 30 inches. Strap-leaf produces smaller leaves and reaches heights of less than 12 inches.
Caladiums prefer nutrient-rich soil high in organic matter. Well-rotted manure or compost added to the existing soil promotes rapid growth and rich color. Amend soil by adding one part organic matter to two parts existing soil and mix in well. You may add peat moss or leaf mold instead of compost or manure.
Caladiums prefer moist soil but suffers if the soil becomes waterlogged. Because of their large leaves, caladiums lose water rapidly, making them susceptible to wilting or damage from a lack of water. Water caladiums often to maintain evenly moist soil. Deep watering once a week is preferable to frequent shallow watering, as it encourages deep root formation. Frequent shallow watering encourages roots to form near the surface. Mulch around the base of caladiums to conserve water.
Caladiums benefit from an application of balanced fertilizer, such as 10-10-10 or 8-8-8, when planted and supplemental fertilizer once a month during the growing period. Mix fertilizer into the soil to prevent injury to the plant's roots or foliage. You also could instead apply water-soluble or foliar feeder to reduce the risk of injury from fertilizers.
Caladiums prefer partial to full shade, but newer varieties will survive in some direct sunlight. Those grown in direct sunlight generally fail to produce brightly colored foliage, and the leaves develop more green than color. One or two hours of direct sunlight is the most they can tolerate without suffering from moisture loss through respiration and leaf burn from the hot sun. Direct sunlight in the morning is preferred.
Caladiums can be grown outdoors during the summer months in most parts of the United States but must be moved inside when temperatures drop in the fall. These tender annuals cannot tolerate frost. Caladiums grow quickly and reach maturity in one season. Store tubers in an area with temperatures of 60 degrees to remain viable for the next season’s growth. You can grow caladiums year-round inside the home as an attractive houseplant.