This fun holiday was invented in Minnesota to honor the brave St. Urho, who chased the grasshoppers out of Finland and saved the grape crop. It just happens to be the day before the holiday for a slightly better-known saint from Ireland.
The legend of St. Urho says he chased the grasshoppers out of ancient Finland, thus saving the grape crop and the jobs of Finnish vineyard workers. Communities celebrate the accomplishment with parties and festivities decorated in the traditional green (for grasshoppers) and purple (for grapes).