Most people enjoy receiving flowers to celebrate a special occasion. If you have a friend or relative who's performing in a play, you might want to show your good wishes and appreciation with flowers. Just as etiquette extends to most areas of life, it also extends to the theatre, which is also deeply shrouded in superstition. Follow the proper theatre protocol so the actor receives your flowers without complications.
The theatre has a myriad of superstitions, so it's not surprising that some of those superstitions relate to actors receiving flowers. It's considered bad luck to present an actor with flowers at the stage door before a performance. To the actor, this is a bad omen. Presenting flowers to the actor after the performance is good luck for future performances. Some theatre companies still honour the tradition of giving flowers stolen from a grave to the director or leading lady. This superstition is rooted in the time when actors were very poor and didn't have money to spend on flowers.
Before the Performance
Actors who have a dressing room often appreciate receiving flowers before the performance. It's best to have the florist deliver the flowers in a vase with a note of good wishes. Never say "Good luck" to an actor before a performance, though. Include a note that says "Break a leg," as a way of offering good wishes. Usually the stage manager won't let people go backstage to deliver flowers in person, but the stage manager might deliver them for you.
After the Performance
The best time to give flowers to a performer may be after the performance. Some theatres won't let you go backstage, but you can meet your friend in the lobby to give him the flowers. You may also be able to give them to the stage manager, who will have a stage hand present the flowers to the actor on stage at curtain call. Don't sit in the audience holding the flowers during the performance, though. Ask an usher to suggest a place -- perhaps the cloakroom or a closet.
Throwing Flowers onto the Stage
Movies often portray audience members throwing flowers onto the stage during the curtain calls, but most theatres don't allow this practice. Check with the box office or other theatre personnel in advance. If it's permissible to throw flowers, gently toss just one, perhaps a rose, at the actor's feet.