In 1923, a year after a New York Times article declared the pawpaw “the most neglected of American fruits,” Zimmerman began a breeding program, with the encouragement of David Fairchild, at his home in Piketown, Pennsylvania, after collecting all the known pawpaw varieties from various sources. He spent nearly two decades breeding pawpaws until his unexpected death in 1941. At that time, his widow donated a portion of his collection to Blandy Experimental Farm in Virginia, and even though others were growing pawpaws, nothing was being done with Zimmerman’s research or his trees.
In 1975, Neal Peterson tasted his first pawpaw. He was a master’s student studying plant genetics at West Virginia University and hiking a path along the Monongahela River in the university’s arboretum when he stumbled onto a pawpaw patch. The aroma of ripe fruit had alerted his senses. He picked up a fruit that lay on a bed of autumn leaves, split it in half, and took a bite. The experience was transcendental. He wondered why something this good had not yet been domesticated. Perhaps it was this very moment that provided him with the motivation to take on the task of bringing the best tasting pawpaws to people.
Before he began the largest and most ambitious scientific breeding program for pawpaws, he did an extensive literature search to find named cultivars and the people who had grown them. This not only took him on a journey through decades of research but also to the places where they had been grown, including Zimmerman’s old home in Pennsylvania and Fairchild’s in Maryland. There were no orchards on the properties—the Maryland Beltway had even paved over Fairchild’s trees. Peterson travelled to Blandy in Virginia to see what remained of Zimmerman’s collection. What he found were a row of five trees in the woods behind the headquarters. He returned in September to taste the fruit and collect seeds. The fruit was exceptional.
During the 1980s, after accepting a job as a USDA agricultural economist in Washington D.C., Peterson planted roughly 1500 seedlings at the University of Maryland Wye Research and Education Center and the university’s Western Maryland research center in Keedysville. For the next several years, he devoted his weekends and vacations to his trees, volunteering friends to help tend to the orchards and taste the fruit. By 1996, Peterson had selected the eighteen best varieties from his fifteen hundred trees.
Before we go any further, the fact that Indigenous people were the first to cultivate pawpaws but many today have never tasted a pawpaw makes this a more complex subject, one that some people tend to ignore. Early woodland cultivation of pawpaws led to the superior genetic material used by 20th century experimental breeders. Tribes with settlements in river valleys foraged, grew, ate, and used pawpaws. It was a seasonal food staple. The Iroquois are even thought to be responsible for the pawpaw’s northernmost distribution in Ontario and western New York.