Impulse buy- calla lily

The calla lilies looked so good in the garden centre today I bought one to give to my Mother-in-law for her birthday. I have to admit I knew nothing about them - according to the book, treat them like dahlias: cover up or lift in the winter as they are not fully hardy. They are also called arum lilies and Zantedeschia aethiopica. They are native to Africa and one of the local names is pig's ear- not so romantic, eh. Well Mam I am giving you a pigs ear- maybe I won't tell her.