Do deadhead the older flowers, because that will encourage more bloom. I usually feed mine bulb food when I plant them and then treat them like other bulbs (altho they are tubers, they can be treated the same), by feeding them bulb food in early spring and then in the late fall again.

Someone else may treat theirs differently, but since they are actually tubers, I treat them like my other tubers/bulbs/rhizomes.

Susan