Question of the Week Number 2: November 9, 2017
“Neil, What should I do with my caladiums over the winter?”
First things first, you should not leave caladiums in the ground if you’re in a part of Texas where temperatures drop into the high 20s or colder. They will be killed by the freezing weather. Even in frost-free parts of Texas they aren’t really considered to be dependable perennials.
To save caladium tubers (not really bulbs) from one year to the next in colder areas: dig them before they’re exposed to the first hard freeze. Don’t wash them, but shake excess soil off them and lay them on newspapers to dry for a few days, preferably in the garage or a shed (definitely not outdoors).
Dust them with sulfur, then place them in shallow boxes filled with dry perlite or sawdust, making sure no two touch one another. Do not stack the tubers in layers within the boxes.
Place the boxes in a dry and warm (60F) room over the winter. Do not replant them until soil temperatures are quite warm in the spring. (They are tropical plants.) In South Texas that would be mid- to late April, early May in North Texas. You could move those dates forward somewhat if you started them in pots in a warm greenhouse.
Your plants next year, assuming all goes well with the storage, will have somewhat smaller leaves, so be prepared to mass them more closely together.
Or, you may decide, as most of us who have already tried this one time have, simply to buy new tubers or transplants each spring. It’s just not worth all the effort. Plus, sulfur isn’t the best air freshener for a long winter indoors.