CHICAGO -- There is history and then there is the stuff of myth and legend. The origin of the ivy that clings to the brick outfield wall at Wrigley Field has a little bit of everything intertwined.

The story that has persisted for generations has been that Bill Veeck Jr. -- the Hall of Fame executive and promoter -- not only came up with the idea for the ivy, but planted it in an overnight operation in 1937. Veeck himself helped perpetuate that tale in an autobiography.

"Greatly exaggerated," Cubs historian Ed Hartig said of the claims of Veeck's involvement. "The ivy was planted by the Clavey family."

This is where history overtakes myth.

Hartig noted that the Clavey family -- who operated farms and nurseries in the area dating back to the late 1800s -- cared for properties belonging to the Wrigleys (owners of the Cubs) in both Illinois and Wisconsin for years. It was the Claveys who sold the ivy to Phillip K. Wrigley for the installation in '37.

As Hartig also detailed to MLB.com for a 2014 series celebrating Wrigley Field's 100th anniversary, a photograph taken by George Brace helped solidify the timeline. It showed the ivy being planted under the direction of Elmer Clavey, with the help of his son, Gordon. The date of Sept. 4, 1937, was written on the back of the photo.

That is nearly a month before Veeck -- the son of former Cubs president William Veeck Sr. --claimed to have planted the ivy.

What is true is that the Cubs made some significant changes to Wrigley Field in '37. They brought in a new scoreboard, updated the outfield wall and bleachers and took steps to beautify the ballpark. Wrigley (son of former Cubs owner William Wrigley Jr.) wanted to give the stadium a park-like feel.

It is not clear if Veeck suggested the ivy, but part of the story that has persisted is that he had seen it at two other ballparks (one in Indianapolis and another in Pasadena, Calif.) and Wrigley liked the idea. The Cubs called the Pasadena site home for Spring Training when Veeck was just a young boy.

No matter how it all started, the Clavey family (perhaps with some help from Veeck) is responsible for planting the Boston ivy, mixed with Japanese bittersweet vines to help expedite the growing process.

The ivy makes Wrigley Field unique, and gives it an artistic look that remains a beloved element of the ballpark to this day. The bricks might be exposed come Opening Day, but the ivy on the wall blooms in a rich green by mid-summer. And, if the Cubs are fortunate enough, they play long enough to see the ivy change colors in October.