How to Propagate Colvile butterfly bush?
Propagate by semi-ripe cuttings in summer

Colvile butterfly bush · Buddleja colvilei
Needs a sunny, sheltered spot with excellent drainage; in areas prone to winter wet, it may be best grown in containers and overwintered in a cool greenhouse. See buddleja cultivation for more detailed advice
Propagate by semi-ripe cuttings in summer