Plantings of caladiums generally begin to look tired and less attractive in late September or early October. When they do, it’s time to decide what you want to do with them. Your choices are 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 reasonably well in full sun (with proper selection of variety), but, they are at their best when planted where they receive part-shade to part-sun in beds that are 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 or bigger than the ones you planted). These tubers can be used to grow caladiums next year, either left in the ground or stored and replanted.
If 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. If that’s the case, you may choose to discard them and purchase new tubers next year.
You may simply leave the caladium tubers in the ground if the bed where they are planted will stay relatively undisturbed. Because the ground does not generally freeze in Louisiana during winter, the tubers may survive the cold and come up next year. It would be a good idea to keep this area well mulched over 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.
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 drier when dormant. If the area where the caladiums are growing tends to stay wet for extended periods, 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 plants.
You may follow both procedures. I have some caladiums planted into ground cover under oaks where the beds remain undisturbed and are well drained. I leave caladiums in those beds over winter, and they have reliably returned for many years. In other areas, I lift and store the caladium tubers to get them out of the way for new plantings of winter bedding plants.
Caladiums should be dug when most 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 yellow or brown. Caladiums are usually ready to dig sometime from late September to mid-October. 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 store room).
Allow the leaves to dry 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 a large amount of soil is 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 before storage.
When dry, they are ready for storing over 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.
Dan Gill is a horticulturist with the LSU AgCenter. He can be reached at DGill@agcenter.lsu.edu