We prefer to wait until the soil has warmed up during April to plant Caladium bulbs. If Caladium bulbs are exposed to cold damp conditions the risk of losing them from fungal diseases is greater. Caladiums will respond to warm soil by rooting and sending out leaves quicker. This is why many professional growers "force" Caladiums by placing trays of moist potted bulbs in special heat tents to keep them warm.