In accordance with Croatian wedding custom, rosemary is offered for pinning to lapels and blouses of wedding guests. Tradition maintains that rosemary (wrapped in the traditional colors of the Croatian flag) wards off evil.
The Rosemary Buttonhole As guests enter the reception, they are greeted with a stem of rosemary wrapped in ribbon (usually red white and blue) which is pinned like a buttonhole to their left side as a sign of welcome. In Croatia, guest normally leave a donation for their rosemary buttonholes for good luck. Croatian Wedding Traditions | Fly Away Bride