I live in an apartment complex in Florida, so all of my plants are in pots on the veranda. I have two Calla Lillies that have beautiful folliage, but haven't bloomed for the past two seasons. When I purchased them, one was white and one was lavender. I cut them down every fall, and they come up in the spring when I resume watering them. The folliage is gorgeous, but they don't bloom. Any suggestions?

Barbara