I have had Cerinthe for a few years now,although I don't know if its called "major"Don't think they mind,but prefer sun.I had some seeds given a few years ago,and they self seed everywhere.some have even come up after the winter.They are not deep rooted ,so shouldn't be a problem with your soil.If there is a different variety,I'm sure someone will put you in the right direction,about yours.....