If it's a "flower" stalk, then cut it off. It's not a particularly striking flower and you want all the nourishment to go to the plant's leaves. I usually keep mine in big pots (with other plants) and they always come back. Our "soil" is mostly sand and very poor. However, I did put some in the ground because they were left-overs and was pleasantly surprised. The caladiums should last a lot longer than a week.
@dyzzypyxxy maybe you have a different variety. Mine always come up very early in the year; I had some in April and they're all putting on a show right now.
Here's the ones in the ground
Here are some in a pot
