My son and his girlfriend have a butterfly farm in the basement. Don't know a lot about it. I think they collect eggs in the flowerbeds, hatch them, raise them and then release butterflies. I know they feed them milkweed.
I gathered up some seed from some roadside plants a few years ago and got it started on the edges at my place. My bees really work it hard, along with the butterfly plants ( milkweed family ) there. I normally see a few monarch caterpillars as a summer bonus. All flowering weeds are welcome at my house.