First make sure it is not considered a noxious weed in your state.In Oregon it is considered a weed.If not ,you can take cuttings 6"long.Place these in a tray of good potting soil.Water well.Place outside in a sheltered are out of direct sun.Water when soil is dry.Don't let it dry completely.When sprigs are a little hard too pull when you try usually means they are getting roots.New growth should start and then you can transplant them.