Expert: Kenneth Joergensen - 7/23/2006

Question
Hi Ken...I live in southern Missouri and have alot of shade to deal with in my yard. So I've found that caladiums are a great selection for me and I would like to be able to store these bulbs (tubers) overwinter and need some instrution on how to do that. Any info on this matter will be greatly appreciated. Thanks in advance. Sorry but I'm not sure as to which growing zone I'm in...Sue Webb

Answer
Southern Missouri would be gardening zone 6

http://www.growit.com/bin/USDAZoneMaps.exe?MyState=MO

In late September, before the soil temperatures fall too low in October, dig the caladiums (they are shallowly planted, but dig the bulbs with lots of soil).

Wash the soil of the tubers but do not remove the stems yet.

Place in an area which is dry and at room temperatures (minimum 65F but out of direct sun) and let the stems die back (I use our attached garage). When the stems are dry, cut the stems a few inches above the tuber (do not cut into the tuber).

Store the tubers dry and warm (70F). You will find that they harden up over a couple of months.

In late spring, place the tubers in a warm bath of water (70-80F, no warmer) and let soak for 7-10 minutes. Then remove and plant the tubers and cover with 1" of soil. Keep warm (minimum 70F soil temperatures) until sprouts show. Then transplant outdoors.

Note: better to be a little late with tubers because planting in cool soil of spring can rot them. They need to be planted in warm soil to avoid rotting. Even so, some may rot during storage.

Healthy tubers, I prefer to plant in pots indoors and keep them on top of the fridge or other warm place for 2-3 weeks until the sprout is well out of the soil. Then you must move to a sunny window (avoid cool drafty ones, though). After soil has heated in late spring (no earlier than June 1st in your area) you can plant outdoors.

Transition the pots outdoors gradually ("hardening off"). Do this by putting pots outdoors during the days first but bring in at night. Remember that these are tropical plants and they do not like cold winds and hate cold soil.

After a few days, you can let the stay outdoors at night and a few days later, you can plant. With caladium the general rule is to keep them warm, and do not be in a hurry to get them in the soil in spring.

I recommend that you harvest the tubers by end of september as they rot quickly in fall.