Yard and Garden: Add colors of Caladium to shady areas

AMES — The multi-colored foliage of caladiums brighten the dark, moist areas of gardens where blooming flowers may not grow as well.

Caladium heart-shaped leaves of green, white, red and pink can be grown in containers or clumped together within beds and borders. Use these tips from horticulturists with Iowa State University Extension and Outreach to add caladium to a home garden.

To have more questions answered contact Hortline at 515-294-3108 or hortline@iastate.edu.

How do I establish caladiums in my garden?

Caladiums (Caladium x hortulanum) are grown for their colorful foliage. They can be purchased as plants or tubers. Plants are available at greenhouses and garden centers in spring. Tubers can be purchased at garden centers and mail-order nurseries.

When should I plant caladium tubers indoors?

Caladiums can be enjoyed for a longer period in the garden by starting them indoors in late winter. Plant caladium tubers indoors four to six weeks before the average last frost date in your area. Tubers should be planted 1 to 2 inches deep. When planting the tubers, place the knobby side up. The knobs are the tuber’s eyes or buds. After planting, place the containers in a warm, 75 to 80 degree Fahrenheit location to facilitate sprouting.

When foliage appears, move the plants to a sunny window or place them under fluorescent lights. Before planting outdoors, harden or acclimate the caladiums to outdoor growing conditions. Initially, place the plants in a shady, protected location and then expose them to short periods of sunlight over several days. After they have been hardened, plant the caladiums in a favorable garden location.

When should I plant caladiums outdoors in the garden?

Caladiums are tropical plants. They like warm temperatures. It’s best to wait until mid-to late May in Iowa to plant caladiums (plants and tubers) in the garden. Tubers may rot if planted too early when soil temperatures are still rather cool. Soil temperatures should be at least 70 F.

What are the site requirements for caladiums?

Caladiums perform best in moist, well-drained soils in partial shade or filtered sunlight. Sites in partial shade receive two to four hours of direct sun. Exposure to too much sun will cause their leaves to scorch. Plants can be grown in containers, as specimens, or massed in beds or borders.

How do I care for caladiums during the growing season?

Caladiums like a consistent supply of moisture during the growing season. In beds and borders, water plants on a weekly basis during dry periods. To help conserve soil moisture, apply a 2-inch-layer of mulch around plants. Caladiums in containers should be checked frequently and watered when the potting mix begins to dry out.

Caladiums have a moderate fertility requirement. In outdoor beds, apply a balanced, slow-release fertilizer and incorporate it into the soil before planting. Fertilize caladiums in containers with a dilute fertilizer solution every two to four weeks.

Are caladiums winter hardy in Iowa?

In Iowa, caladiums are tender perennials. They will not survive the winter outdoors. If you wish to save caladiums, plants must be dug up in fall and stored indoors over the winter months. Carefully dig up the caladiums when the foliage begins to yellow with the onset of cool fall temperatures or wait until after the first frost. Place plants in a warm, dry location for one to two weeks to cure. Afterwards, cut off the dry foliage and place the tubers in a small box. Cover the tubers with dry peat moss, wood shavings or vermiculite. Store the tubers in a cool (60 to 65 F), dry location.