Marilynne
Mine don't go outside until May too.
Typically, when I put calla bulbs away for the winter, I take them out of the soil and put them in brown paper bags and then up int my attic to overwinter. This allows me to inspect the bulbs for problems.
I tried one year to overwinter them in their pots, but they have consistently done better for me when removed from the soil. I don't know if it is the fact that I can get rid of any bulbs that show signs of disease or that they get new soil in the spring as to the better performance.
Carolyn
