i leave mine until they either fall off or even better re-bloom. Many of mine re-bloom on old inflos. Usually not as intense but still a few flowers.

I do the same as Mike. Not only can it continue to throw more blooms, but maybe even a seed pod.

Oh okay...I'll let it go and see if it will rebloom again, Thanks!!

forgot to say that in a more rare instance it has been reported that some old inflo's have turned in to branches.