Caladium is a shade-loving perennial that is grown for its exquisite foliage. Its low profile and broad colorful leaves blend well with other plants that thrive in conditions from partial sunlight to deep shade. You can grow caladium hortulanum and caladium bi-color varieties outdoors from bulbs in climate zones 7 through 11. In cooler growing areas the bulbs cannot endure winter temperatures, but will thrive indoors in containers. Follow these steps to plant and tend caladium bulbs for optimum growth.
Step 1 - Choose the Color and Leaf Shape of the Caladium
Caladium comes in many varieties with leaves shaped like spades, hearts, arrows and lances. Their foliage can be green with white and veined in dark green (Christmas Caladium), pink in the center with a border of white and green (Rosebud Caladium) or nearly all pink with a deep green edge (Sweetheart Caladium). The Christmas and Rosebud grow best in partial shade conditions, while Sweetheart is a deep-shade plant.
Step 2 - Plant Outdoors in the Spring in a Shady Spot
Plant caladium bulbs outdoors in rich organic soil. To ensure well-drained soil, mix in medium grain sand or pebbled stones, with a layer of this material below the bulb as well.
Plant in clumps so the foliage can mass together for the best color effect. Most caladium prefer shade, so choose a location under a pine, spruce or cedar tree.
Step 3 - Plant Up to 2 Feet Apart
Plant the caladium bulbs up to 2 feet apart, as this is the plant's maximum width at maturity. The leaves will overlap a bit but this poses no problem to their health. It will also emphasize their color and shape as a focal point in a shaded area.
Add hellebore, polka-dot plants or other shade-favoring plants to a grouping with caladium. If the caladium start to become crowded, propagate new plants from the bulbs, which divide cleanly and easily.
Step 4 - Watering and Fertilizing Caladium
After bulb planting, water the soil thoroughly, and let it dry down a few inches before adding more water.
In hot summer conditions, water your caladium more often, but make sure the soil does not become soggy. This will promote leaf-destroying fungus diseases.
Use a high-nitrogen fertilizer to aid leaf development when they are first planted.
You will not need to add any more during the growing season.
Step 5 - Grow Indoors in Containers
Choose a small, very low variety such as the Jackie Suthers Caladium. It has slender lance-like leaves with slender white borders framing a dark green center.
Plant one bulb in a large container, at least 18 inches across. Use potting soil with peat moss added, and fertilize with a high-nitrogen fertilizer to promote leaf growth.
Follow the label directions and make it the recommended strength for a container plant; about 1/2 times as concentrated as for plants in the garden. Divide the caladium after two years, or sooner if it becomes root-bound, producing fewer leaves in duller colors. You can divide the bulb easily and plant those sections that have root growth already evident.