Pathologist, Christmas tree farmer Jon Kosek dies at 90

An outdoor enthusiast, bicyclist and founder of a Christmas tree farm, Kosek was a staff pathologist at the VA Palo Alto Heath Care System for nearly 45 years, mentoring hundreds of residents and students.

- By Krista Conger

Jon Kosek

Jon Kosek, MD, clinical professor emeritus of pathology, died Oct. 16 at his home on the Stanford campus. He was 90. 

“Jon Kosek was a dedicated teacher and an expert pathologist who devoted decades to his field,” said Lloyd Minor, MD, dean of the School of Medicine.  “Countless trainees and colleagues benefited from his wisdom and guidance. He will be missed here at Stanford Medicine, and his influence in pathology labs across the nation will be lasting.”

For nearly 45 years, Kosek was a staff pathologist at the Veterans Affairs Palo Alto Health Care System, where he mentored hundreds of pathology residents and medical students and performed countless autopsies. His colleagues remember him as an enthusiastic, kind, generous and patient teacher. 

“Jon was a lovely man, and he was incredibly smart and knowledgeable about a wide range of subjects,” said John Higgins, MD, professor of pathology at Stanford Medicine. “His wisdom was accentuated by his tendency to speak so softly that it could be difficult to hear what he was saying, but one quickly learned it was worth paying attention. He was the pathologist who knew everything and did everything.”

Kosek began his career with the VA Palo Alto Health Care System in 1964 and retired in 2009. He was an active and avid outdoorsperson with a horticultural bent. In 1965, he and his wife, Margaret, bought property on the coast in Pescadero, California, where they started a cut-your-own Christmas tree farm that’s still in operation. 

“Jon loved the outdoors, especially his Christmas tree farm, Rancho Siempre Verde, on the coast,” said Sara Michie, MD, professor emerita of pathology. “Until a few years ago, he ran dozens of miles before breakfast every day, and rode his bike on weekends to the tree farm, where he planted and cared for trees, and had lots of fun with family, friends, chain saws, bulldozers, backhoes and dogs.”

“My father was nearly endlessly patient, and he enjoyed helping the many young people who had their first jobs working at tree sales during the Christmas season,” said his daughter Ann Akey. “He commuted by bicycle to his job at the VA, initially on a one-speed bike, then on a three-speed and eventually a 10-speed. He enjoyed longer weekend rides to the coast long before road biking became popular. He led a very active life, physically, intellectually and socially.”

Kosek was born Sept. 22, 1930, and raised in Cedar Rapids, Iowa. He attended Cornell College, then medical school at the University of Iowa. He completed his residency at Boston Children’s Hospital before moving to Palo Alto in 1960.

He is survived by his wife, Margaret; their children Ann Akey of Stanford; Jon “Jake” Kosek of Berkeley, California; Margaret Kosek of Charlottesville, Virginia; Mary Kosek Patz of Aptos, California; and Peter Kosek of Eugene, Oregon; and 12 grandchildren. 

About Stanford Medicine

Stanford Medicine is an integrated academic health system comprising the Stanford School of Medicine and adult and pediatric health care delivery systems. Together, they harness the full potential of biomedicine through collaborative research, education and clinical care for patients. For more information, please visit

2023 ISSUE 3

Exploring ways AI is applied to health care