Marijuana joined roses and dahlias Friday in blue ribbon events at the nation’s first county fair to allow pot competitions. This weekend’s Denver County Fair includes a 21-and-over “Pot Pavilion” where winning entries for plants, bongs, edible treats and clothes made from hemp are on display. Organizers say the marijuana categories this year — which come with the debut of legal recreational marijuana in Colorado — add a fun twist on Denver’s already-quirky county fair, which includes a drag queen pageant and a contest for dioramas made with Peeps candies. “We’ve been selling tickets to people from all over the...