storing calla tubers
If you overwinter your callas, they’ll get bigger and bigger, producing a better show every year.
A light frost (30 to 32 degrees F) will kill the foliage without hurting the tubers. Let the foliage dry for a day or two. If a hard freeze (28 degrees F or colder) is in the forecast, dig the tubers as soon as possible or they may be damaged by the cold.
Lift the clump and snip off the foliage a couple of inches above the tuber as I’m doing in the top photo. Crumble off big clods of soil. Set the clump in a shady spot where it won’t freeze. Allow the soil to dry completely — this could take a few days. At this point, the roots and stem should be dry enough to come off easily. It’s critical that the tubers are completely dry before you store them because they’re prone to rotting during the winter.
I like to bury my tubers in dry peat moss in a plastic-lined cardboard box as I’m doing in the lower photo. (Wood shavings are also good storage material.) Make sure the tubers aren’t touching each other. If one rots, the rest may rot, too. Poke holes through the plastic and the side of the box, then loosely close the tops. It’s OK to stack boxes on top of one another.
Check your boxes a few times over the winter and remove any mushy tubers. Keep your callas in a cool, dry place that stays about 50 to 55 degrees F during the winter — an unheated basement or attached garage works well.