If you mean the common white calla, they need a lot of water and rich soil. Mine are in the ground in a sheltered location that is part sun. I would not put it in full sun in a container, but it should do okay if it is in part sun to part shade with a lot of water. Southern living garden guide says they thrive in moist even boggy soil. Maybe you can try putting a saucer of water around the base of your pot so that it can soak up water and see if that helps it on the front porch.

I have a friend with calla lilies growing in the ground in dappled shade. They look so pretty that I am going to try some next year.

I grow calla in a container in morning sun/afternoon shade conditions in S. LA. They are very easy to grow and blooms hold for a long time. I usually dig them up and overwinter indoors , if they were in the ground I could prob. leave them overwinter. They are also one of the first bulbs to bloom and like alot of water.

I've never dug mine up & they do well, like everyone else, in part shade.
Nancy