Caladium, a tropical foliage plant native to South America, produces ornamental leaves in various shades of red, pink, green and white. The multicolored foliage features a variety of patterns with contrasting backgrounds and colored veins. Gardeners commonly use caladium to create a focal point in the landscape, as it provides a striking contrast with the green leaves of other plants. Although popular throughout the United States, caladium plants cannot tolerate cold temperatures and require special care to survive winter in most areas of the country.
Site and Soil
Caladiums require dappled or moderate shade throughout the day for optimal growth. Some varieties can tolerate brief periods of direct sunlight, but all types thrive in a shady location. Too much shade, however, may result in dulled colors. Light sun in the morning hours and full shade in the afternoon usually yields the best results. Fertile, well-drained soil provides the best growing medium for caladiums. In areas of poor soil, gardeners often amend the planting site with organic compost before planting.
Caladium tubers need warm, moist soil to grow and thrive. A soil temperature of 70 degrees Fahrenheit at planting time will ensure the tubers do not rot. Planting the tubers 1 inch deep in the soil allows the sprouts to easily break through the surface after growth begins. A thin layer of mulch, between 1 and 2 inches deep, applied after planting insulates the soil, prevents the establishment of competitive weeds, and improves moisture retention. For the best results, caladium tubers should be spaced at least 1 to 2 feet apart.
Regular watering about once every three to five days ensures the soil stays consistently moist, a necessity for the plant's survival through the summer months. Watering caladiums requires a delicate balance. Moist soil prevents leaf drop, though saturated or soggy soil may cause the tubers to rot. Watering when the soil surface feels dry to the touch is best. When temperatures begin to drop in fall, the plant's foliage will sag. Reducing the watering frequency to once each week at this time prepares the plant for winter.
Caladiums benefit from regular fertilizing, about once a month, during the active growing season. An equal analysis 10-10-10 NPK liquid or granular fertilizer provides proper nutrition for healthy, large, colorful foliage. Dry soil during fertilization may cause damage to the tuber, but light watering prior to feeding prevents this problem. Cease fertilization in early fall to help the plant acclimate to winter dormancy.
In zones 10 and 11, caladium tubers require no special winter care. Plants grown from zone 9 northward, however, cannot survive the cold and must be overwintered indoors. Digging up the tubers in fall before the foliage has lost all color and allowing them to dry for about a week adequately prepares them for storage. Once dry, remove the foliage and store the tubers in peat moss at around 50 degrees until the following spring. The tubers should not touch during storage. Due to the lack of color in second-year foliage, many gardeners choose to simply discard old caladiums and plant new tubers each year.