Care of Sunflowers and pruning

I've had some challenges growing my Lemon Queen's, but finally I have three big healthy flowers and four more just coming up.

However, I can't find consistent information about the care and/or pruning of the flowers? Once they are done they begin to wilt and look pretty pitiful. So, how do I care for them? Do I prune the old flowers back and will new ones sprout?

What is the best care for these beauties?

Pruning

I prune mine. Mine are still adding new flowers

I prune mine. I just cut the

I prune mine. I just cut the wilted flowers off with pruning shears. They seem to sprout new flowers. Hopefully they will continue flowering until the first frost.