The caladium, from the aroid family, is known for the bright, attractive foliage it produces. The plant is hardy in USDA growing zones 3 through 10, but requires indoor tuber storage during the winter in cold growing zones. Caladiums grow well in containers and hanging baskets or when planted in partially shaded areas, to add a splash of color.
The caladium is a tuber root growing plant that has colorful foliage leaves and reaches a height of 12 to 30 inches depending on the variety. There are two plant shapes with leaf colors in the combinations of white, pink, red, green and yellow. Fancy leaf varieties have a large, heart-shaped leaf on long petioles, while the strap leaf varieties have a thick, narrow leaf on short petioles. Strap leaf plants are short and compact in size.
Caladium plants grow best when planted in a moist soil that has a minimum temperature of 70 degrees F. Cool soil will limit plant growth. The area should be partially shaded or offer full sun during the morning hours with shade in the afternoon. Caladiums will grow in a fully shaded area, however the foliage will not be as brightly colored. Test the soil pH prior to planting caladiums, as they prefer an acidic pH of 6.0 to 6.5. Ground rock sulfur can be worked into the soil 2 to 3 weeks prior to planting, to lower the pH.
The caladium plant requires a moist, but not wet, soil during the summer growing season. Irrigate the plants when the weekly rainfall amounts are less than one inch. Placing a 2- to 3-inch layer of mulch around the plants will assist with soil moisture retention. Caladium plants are heavy feeders and should be fertilized every 4 to 6 weeks during the growing season with a 5-10-10 fertilizer at a rate of 1 tablespoon for each square foot of soil. Container-grown plants should be fertilized with 1 teaspoon of fertilizer for each container. The plants should be generously watered after applying fertilizer to prevent foliage burn. Store caladium tubers indoors during the winter months in USDA growing zones 7 and lower.
Caladium plants can be propagated to produce new plant clumps by dividing the tubers. Dig the entire plant from the ground and set it in a shaded location to prevent the tubers from drying during the process. Divide the tubers by gently pulling or cutting the tubers apart. Small tubers with few eyes or leaf buds will produce smaller plants.
The caladium plant is susceptible to tuber rot and leaf burn. Tuber rot forms when they are stored in a cool temperature with high humidity. The tubers will become soft and slimy or appear dry with a chalky residue. Discard tubers that have signs of rot. Leaf spot is a fungal disease that causes the lower leaves to form tan or brown spots. Remove and discard infected leaves to prevent spreading the fungus.