February is just fine. We'll have cold, we'll have warm and buddleias bloom on new growth. Even after first bloom, if you remove the spent tips you can encourage new growth and bloom during the season.
They're pretty durable plants once they settle in.

thanks! mine did so wonderful last year i didnt want to kill them,or shock them

jilliebean, the only things you don't want to prune for sure at this time of year are things that are hollow stemmed like salvias. Opening that hollow to rain then frost channels the wet to freeze the root/root rot.

I prune mine when I need the cuttings for pea steaks. Which means right about now, because it's pea planting time.