I really wanted to grow these out back under the trees. No luck. I tried for two years and finally gave. Calla lilies need lots of sun. I now have a patch happily growing in a small bed near the front door where they receive full sun all afternoon.
They do not like to be dry. Stick them in a wet part of your garden or plan to water them daily. Or pot them up and put the pot in a shallow part of your pond. In the wild, in Africa, they grow in marshes.
The flowers are not the colored petal at the top of the stem, that protects the flower. The flowers are very tiny and inside of the spathe which can be white, pink or yellow, leaves are heart or arrow shaped.
There are six species of calla lilies, some are evergreen some are deciduous.
Most calla lilies grow to between 12″-18″ there are some larger varieties that will grow to 24″ and have much larger flowers.
Plant the bulbs in the fall about 3″ to 4″ deep. In time they will multiply and fill in an area so leave a little room between the bulbs.
If they are exposed to wind you may need to stake the flowers, they do best tucked up near a house or fence where they are sheltered.