Carolyn Wharton caladium (for Oct. 11) (Photo by Dan Gill)

It’s time to dig caladiums when the foliage turns brown and papery. (for Oct. 11) (Photo by Dan Gill)

For Release On Or After 10/11/13

By Dan Gill
LSU AgCenter Horticulturist

Caladiums are among the most reliable summer bedding plants for providing color in shady areas and even in sunny beds. They stay attractive despite the intense heat of summer and are rarely bothered by insects or disease.

By the beginning of October, however, caladiums reach the end of their growing season and decline in appearance. But this is not necessarily the end of them. These plants grow from perennial tubers that can live and grow for a number of years. Now is the time to decide whether to pull them up and throw them away; leave the tubers in the ground to resprout there next year; or dig them up, store the tubers and plant them again next year.

Caladiums tolerate heavy shade and even do well in full sun with proper variety selection. They are generally at their best, though, when planted where they receive part shade to part sun in beds enriched with organic matter and kept evenly moist. If you have provided them with the growing conditions they prefer, your caladiums should have produced nice-sized tubers by this time – as big as or bigger than the ones you planted. These tubers can grow caladiums next year, whether they’re left in the ground or stored and replanted.

Where the growing conditions were not ideal – particularly if they were growing in heavy shade or dry conditions – the tubers may be too small to perform well next year. (They will be much smaller than when they were originally planted.) If that’s the case, you may choose to discard them and purchase new tubers next year.

If the bed where the caladiums are planted will stay undisturbed, you may simply leave the tubers in the ground. Because the ground does not generally freeze in Louisiana during winter, the tubers should survive the cold and come back up next year. It would be a good idea, though, to keep the area mulched this winter to protect the tubers just in case it is unusually cold. Plantings in north Louisiana run more of a risk than those planted in the southern portion of the state.

Cold is not as likely to kill the tubers as wet soil. A bed that is not well-drained and tends to stay wet over winter may cause the tubers to rot. Caladiums enjoy abundant moisture when they are growing, but they prefer to be dryer when dormant. If the area where the caladiums are growing tends to stay wet for extended periods during rainy winter weather, this can be problem, and it would be best to dig and store them.

If you intend to replant the area with cool-season bedding plants, such as pansies, the tubers also should be lifted and removed to allow you to do bed preparation for the new bedding plants.

Caladiums should be dug when many of the leaves have turned yellow and the foliage looks tired and begins to fall over. Do not wait for all of the foliage to turn completely brown and disappear, or it will be hard to find the tubers.

Use a shovel or a garden fork to lift the tubers, being careful not to damage them. Leave the foliage attached to the tubers, shake and brush off most of the soil, and lay them out in a dry location sheltered from rain in a garage, under a carport or in a storeroom.

Allow the leaves to dry for 10 to 14 days until they are tan and papery in appearance. At that time the foliage will easily separate from the tubers, leaving a cleanly healed scar.

The tubers can then be cleaned by washing in water to remove any remaining soil adhering to them. Unless there is a large amount of soil clinging to them, this is usually optional. If you do wash them, they should be air-dried in a well-ventilated place for several days until the moisture has evaporated from the surface of the tubers before storage.

When dry, they are ready for storing over the winter. Throw out any tubers that appear to be rotted or have soft spots. Tubers that you may have accidentally damaged when digging can be saved if they have healed well and feel solid. Gardeners sometimes have a hard time deciding which end is up when planting caladium tubers. If you like, use a felt-tipped pen to mark the top while it is easy to see where the leaves were removed to save yourself confusion next spring.

Place the healthy tubers in an old nylon stocking, a mesh bag (such as an onion sack), a paper bag or a cardboard box. The container should be able to “breath.” Do not store the tubers in a plastic bag or airtight container because this may lead to rotting. Make sure you keep the tubers indoors where temperatures will stay about 70 degrees or above.

Remember that with poor growing conditions, particularly in areas of heavy shade, caladiums produce small, weak tubers that may not return well, whether they’re left in the ground or dug and stored. Under the right circumstances and with proper care, however, the tubers you planted earlier this year can provide a beautiful display again next summer.