Dutch Iris

This is what my mother always called them. Much smaller than the usual iris. Mine have already bloomed and the green flags have fallen over. Should I cut them off or just wait?

I usually wait until the leaves begin to yellow, at which point I figure the leaf has fed the bulb as much as it's able. If you leave the leaves on longer, the bulbs will grow and multiply better... but you won't kill it at this point if you trim it back... some people are really bothered by "messy looking" leaves, but I don't mind leaving them alone until they die back.