Zenger Farm is part of the Johnson Creek watershed, which, prior to European settlement, was heavily forested and was used by Native Americans of the Chinook band for fishing and hunting. In the 19th century, a surge of settlers cleared much of the land for farming. The land upon which Zenger Farm sits was part of a 320-acre donation land claim by William Johnson for whom Johnson Creek was later named. Johnson was a sawmill operator who furnished lumber for some of Portland's earliest homes during the mid 19th century.

The land passed through several owners and eventually was purchased in 1913 by Ulrich Zenger, a Swiss dairy farmer. Zenger operated the Mount Scott Dairy, lived in the farmhouse, and farmed the land. When he died in 1954, the farm went to his son, Ulrich Zenger Jr., who lived on the farm as his father had. Ulrich Zenger Jr. operated the farm but did not maintain it as a commercial enterprise.

It was Zenger Jr., who, with great fondness for the place that had been his home, had the foresight and determination to protect the land from commercial development and preserve its integrity as a farm. In the mid-1980's, Zenger Jr. explored ways to preserve his farm and allow future generations to develop a mutually sustaining relationship with the land and a respect for its heritage, as Zenger himself had done for more than eighty years.

The land was purchased by the City of Portland's Bureau of Environmental Services (BES) in 1994, five years after Ulrich Zenger Jr.'s death. BES saw in Zenger Farm an opportunity to promote environmental stewardship in a way that would complement BES' long-term conservation plans for the Johnson Creek Basin and Watershed. BES preserved the farm and its wetland as a collection point for the area's storm water. It was in June of 1995 that the land became a working farm again. Marc Boucher-Colbert knew good soil when he saw it. He leased the farmland from BES and, through his Urban Bounty Farm, not only cultivated the land but promoted educational and community events on the site. Urban Bounty Farm formed partnerships with the Environmental Middle School and the Portland State University Capstone Program, among others, to broaden the farm's availability as an open-air classroom.

Zenger Farm's expanding role as an educational and environmental resource created a need to formalize the farm's mission and establish a group to maintain it. In 1999, the Friends of Zenger Farm was assembled. They authored the Zenger Farm Master Plan, obtained the City's approval of the Conditional Use Master Plan, and partnered with BES to secure a 50-year lease of the property. Ulrich Zenger Jr.'s family farm was now, officially and sustainably, a public space.