Depending upon the species, late spring to late summer.
Throughout the United States.
Well drained soil that''s rich in organic material.
Water regularly and deeply. For container plants, add water until it starts to drain from the bottom of the container.
When bulbs are available (fall through spring).
When planting, mix 1 teaspoon of bonemeal into the soil at the bottom of the planting hole. During the growing season, feed with an all-purpose plant food.
After the plants have bloomed, allow them to die back, then cut them off at ground level.
Full sun to part shade, depending on the variety.