When Should I Plant My Caladium Bulbs
Caladiums normal growth cycle:
In the landscape, Caladium bulbs typically sprout in the spring beginning in March in the South (i.e. Orlando) and in June in the North (i.e. Chicago), when soil temperatures are greater than 65°F. They grow through the summer and then go dormant in the Fall beginning in September in the North (Chicago) and November in the South (Orlando). North of zone 8B caladiums must be dug up in the Fall and kept above 65°F during the winter to be planted the following spring otherwise they will freeze to death.
Planting outside their normal cycle:
The normal growing cycle for Caladiums in zone 9 and further south, is April-November. Once soil has warmed up caladiums can be planted anytime, however environmental factors will affect their performance. Caladiums have a genetically determined endogenous (circadian) rhythm (growth cycle). Depending on when you plant them, they will try and complete their normal growth cycle however cold weather usually interrupts this. The later you plant them, the less growing time they’ll have until cold weather forces them into dormancy.
When should I plant bulbs purchased at the Lake Placid Caladium Festival (usually the end of July each year)?
Commercially Caladiums are harvested in the late fall and winter (November-February). Once harvested and cured, they remain dormant until planted. With caladiums, dormancy is more of a quiescence as they are still actively respiring, and in doing so, they are consuming stored energy (carbohydrates) from the base of the bulb to survive. In other words, they cannibalize the bottom of the bulb to preserve the life of the eyes on the top of the bulb. This is why the base of the bulb can be papery or hard as tissue contents are consumed to preserve the top of the bulb. This is their life support system. Bulbs need to be planted before their life support system runs out. The larger the bulb the larger the life support system. Therefore, you should plant your summer purchased bulbs right away. They will not survive until the following Spring. Planting them off season (in the summer versus the spring) will temporarily interrupt their endogenous rhythm, so they will not sprout as quickly the following Spring as bulbs that have been grown on their normal cycle. This effect however is temporary and the bulbs will return to their normal cycle in 2-3 years.
When should I plant bulbs purchased at Classic Caladiums open house (usually the first of September each year)?
For the reasons discussed above, bulbs purchased at Classic Caladiums open house should be planted right away. In Florida, they should provide good color until late November and in some cases, you may still have color at Christmas. They will sprout later the following spring but still provide you good summertime color. The following year they should revert to their normal cycle, which in Florida is April-November.