how to get butterfly plant to flower?

Question

should i cut them back or prune them and where?

Answer 1

If you are referring to the butterfly bush, here are the specifics in growing it:

https://www.gardeningknowhow.com/ornamental/shrubs/butterfly-bush/butterfly-bush-not-blooming.htm

If you mean the bright orange butterfly weed, asclepias tuberosa, the native host plant for monarchs, they flower off and on all summer. They bloom, then take a rest, then bloom again.

https://www.gardeningknowhow.com/ornamental/flowers/milkweed/growing-butterfly-weed.htm