Long before Walnut Creek was known for its namesake nut, it was a preeminent grape growing region. In fact, grapes accounted for one third of the agriculture production before disease and Prohibition decimated the industry in the 1920s. Citizens celebrated the community's cash crop in 1911 at the Walnut Creek Grape Carnival. 

Highlights of the event were “aero plane” rides given by Oakland pilot Weldon Cook, a parade down Main Street, and baseball game between the married men of Concord and Walnut Creek. 

By the 1930s Walnut Creek was celebrating other crops: walnuts, pears, and citrus. After the Walnut Festival Association incorporated in 1938, its annual fundraising carnival became Walnut Creek's signature event, and a substantial source of capital for financing ballpark fields and improvements at city pools. But by 1976, City Park could no longer handle the thousands of people who attended the event and it was moved to Heather Farm Park where it remains today.

This year, the Walnut Festivall returns September 22-25 to Heather Farm Park.

Source: Walnut Creek An Illustrated History by Brad Rovanpera