I planted my scrawny butterfly bush last year and it's at least tripled in size in one season. I didn't do anything special to it last year before winter, but I think I'll pay more attention to what needs to be done to ensure it has a good start again next year. Preparing Butterfly Bushes for Winter has good information on doing just what it says.
The butterfly bush draws an abundance of butterflies.
I captured three in this one shot.
Since this bush has done so well, I might try to put another out back (since I spend so much time there with the dogs and chickens). Since the butterfly bush I have is healthy and a good size, I may try to get another plant from it. According to Propagation of Butterfly Bush, it can be done by harvesting the seeds, taking a cutting or dividing the shrub. I don't think I want to dig up the whole shrub, so I'll probably try drying the seeds and maybe a cutting or two.
I can't believe I'm thinking about preparing plants for winter when we're in the middle of a stretch of days with heat indexes over 100.